• Salt-spray crystals / shoreline frosting is an appearance change on glass caused by marine/coastal aerosols (sea salts and hygroscopic constituents) depositing and cycling via evaporation/condensation. It presents as crystalline rings/halos, feathery “frosted” veils on windward façades, and recurring drip/rivulet maps under prevailing winds. With long dwell and contaminant co-deposition, very shallow micro-texture may develop.
• Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Spray-side (#1) accumulation: speckled crystal film, crescent/arc halos aligned with wind gusts; heavier near edges/frames and windward elevations.
• Rivulet/drip maps below head/pressure zones; feathered, matte “shoreline frosting” in raking light from repeated wet/dry cycles.
• Inboard faces (#4) generally clean unless air paths carry aerosol inside (rare).

• Surface-catch class (MSRT)
• SC-0 for loose crystals/films on the surface.
• SC-1 may appear where micro-texture begins from repeated cycles with fines/soils (very shallow relief in raking). SC-2 suggests misclassification—check Ch.03.03 mineral etching or M.02 abrasion.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected on the worked face. MSRT supports classification only.
• Visual signature
• Sparkly crystalline speckle at oblique angles; ring/halo outlines from evaporation margins; feathered matte veils on high-exposure panes.
• No chip-flank sparkle (not scoring); no fused pits/nodules (not hot particle).
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); raking macros to resolve crystal fields, shoreline edges, rivulet maps. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Most common on #1 (outboard) windward façades. If fixed parallax places deposits between panes (#2/#3), classify CAT-5 by location and refer.
• Mechanism cue (context)
• Marine/coastal proximity, salt air, wind exposure maps; salt haze on frames/sills/metalwork; nearby breaking surf or salted road spray (winter).

• Assign CAT by visibility at acceptance geometry and MSRT after a small reveal test. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Discrete crystal film/rings; SC-0; mainly angle/raking visible; clears with proper reveal on test patch. Indicative relief: 0–10 μm (optical).
• CAT-2 (Light): Persistent frosting/shoreline veil after reveal with localized SC-1 (incipient micro-texture from cycling/soils); limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area matte fields / recurrent rivulet maps legible at standard distance with scattered SC-1; indicates long dwell and frequent exposure. Indicative relief: ~40–120 μm (micro-texture stack).
• Reclassify when: Post-reveal, if non-directional micro-texture persists without crystalline residue → assess Ch.03.03 mineral etching; if linear abrasion swirls are evident, assess M.02.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” removal during classification.

• vs. Hard-water mineral system (Ch.03): Hard-water shows ring/runs from drips/sprays with crystalline edges and often silicate/carbonate balance; shoreline frosting maps windward exposure and spray direction; chemistry/location cues matter.
• vs. Detergent/surfactant film (R.04.01): Detergent veils show iridescence and wipe geometry; salt spray shows granular sparkle and shoreline halos without cleaning tool paths.
• vs. Soot/particulate film (E.01.03): Soot is grey/black, dry and transfers to cloth; salt crystals are sparkly/whitish and often deliquescent (re-wet into clear patches).
• vs. Chemical etch (Ch.01/Ch.02): True etch shows modeled micro-texture and SC-class beyond simple residue; salt deposits alone are SC-0 and lift on reveal.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of crystal fields, shoreline edges, rivulet maps; context frames of façade orientation / coastline / windward elevation. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.01.01 Salt-Spray Crystals / Shoreline Frosting — Crystalline deposit / feathered shoreline veil on surface #___ (windward); post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: sparkly crystal field, rivulet map, shoreline halo; no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to Ch.03.03 if persistent micro-texture indicates etch; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Atmospheric corrosion matte is an appearance change on glass driven by acidic or pollutant-laden moisture (e.g., SOx/NOx, industrial emissions) and cyclic wet/dry exposure, producing surface hydration/leaching and very fine micro-texture. It presents as a non-directional, low-contrast milky haze that reduces specular clarity and can map runoff/edge dwell. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Global or zone-specific milkiness on outboard (#1) faces—greatest on windward or pollution-facing elevations.
• Rivulet ghosts or bloom near drip paths, sills, and frame edges where dwell times are higher.
• Under raking: fine, uniform scatter without clear lines, rings, or swirl geometry.

• Surface-catch class (MSRT)
• SC-0 when only residue/films remain pre-etch (reveal patch clears to clarity).
• SC-1 when micro-texture exists (slight tactile interruption without chip flanks); SC-2 uncommon—if present, re-evaluate for Ch.03.03 mineral etching or M.02 abrasion fields.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Non-directional milky matte; loss of “snap” in reflections; no chip-flank sparkle, no discrete pits.
• Rivulet/edge bias: subtle gradients tracing water behavior over time.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use raking to reveal uniform scatter. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Predominant on #1 outboard faces. Between-pane findings on #2/#3 via parallax → CAT-5 by location.
• Mechanism cue (context)
• Urban/industrial corridors, near highways, power plants, cooling towers; lack of wash cycles or poor maintenance intervals; acid rain complaint history.

• Assign CAT by visibility at acceptance geometry and MSRT after a reveal patch. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Slight veil removable on reveal patch; SC-0; visible mainly at angle/raking. Indicative relief: 0–10 μm (optical film only).
• CAT-2 (Light): Persistent non-directional matte post-reveal with SC-1 in zones; limited standard-view impact. Indicative relief: ~10–40 μm (incipient micro-texture).
• CAT-3 (Moderate): Wide-area milkiness legible at standard distance; consistent SC-1; reflects long dwell/high exposure. Indicative relief: ~40–120 μm.
• Reclassify when: Distinct rings/runs with crystalline edges dominate → assess Ch.03.02 Mineral staining; etched fields with directional marks → consider M.02 abrasion overlay; pits/nodules → Th.01 hot particle family.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Detergent/surfactant film (R.04.01): Detergent shows iridescence and tool-path streaks; atmospheric matte is uniform/non-directional and persists after a simple wipe unless only residue was present.
• vs. Mineral system (Ch.03): Minerals exhibit rings/runs and may transition to etch halos; atmospheric matte is more global, edge-biased, and non-crystalline.
• vs. Fabric softener/additive film (R.04.02): Additive films show strong wetting contrast and fragrance; atmospheric matte shows uniform scatter with environmental context.
• vs. Coating anomalies (Co-family): Coating issues are often on #2/#3 or designated coated faces and show color/patchiness; atmospheric matte is substrate-side exposure-driven on #1.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of uniform scatter and edge/rivulet bias; façade context showing pollution sources/windward orientation. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.01.02 Atmospheric Corrosion Matte (SOx/NOx / “Acid Rain”) — Non-directional milky matte with edge/rivulet bias on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: uniform scatter, loss of specular snap, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to Ch.03 if mineral patterns dominate; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Soot / particulate pollution film is an appearance change on glass produced by airborne particulates (carbon soot, diesel exhaust, industrial dust, ash) that accumulate as a dry, grey–black veil. It often shows directional deposition based on airflow, edge build, and finger “lift” windows where casual contact removed soil. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Neutral-to-cool grey haze to flat blackening in severe cases; matte look that dulls reflections.
• Hand/finger wipe arcs that print lighter; drip/rivulet darkening where water carried particulates.
• Heavier loading near roadways, loading docks, generators, chimneys, or parking structures; pronounced on horizontal ledges and frame heads.

• Surface-catch class (MSRT)
• Typically SC-0 (dry particulate on top).
• SC-1 may appear where abraded while dusty (dirty microfiber, paper towels) created very shallow micro-texture; SC-2 suggests misclassification—check for M.02 abrasion fields or Th.01 hot-particle if pits/nodules present.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Dry, soot-like film that transfers easily to a clean cloth; no oily gloss.
• In raking: fine, non-sparkling particulate; no chip-flank sparkle; no fused pits/nodules.
• Deposition bias: darker near upwind edges, exhaust/diesel paths, or stack influence.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); raking macros to show particulate texture and wipe windows. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Common on outboard (#1) faces; interiors (#4) affected in garages/mechanical rooms. Between-pane by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Traffic corridors, bus bays, diesel generators, industrial stacks, wildfire season, forklift aisles; dry black soil on frames/sills that transfers to cloth.

• Assign CAT by visibility at acceptance geometry and MSRT after a small reveal test. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Light soot veil; SC-0; mainly angle/raking visible; lifts completely on reveal patch. Indicative relief: 0–10 μm (optical film).
• CAT-2 (Light): Persistent dark veil with wipe windows; localized SC-1 from prior dusty wiping; limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area darkening legible at standard distance (global contrast loss), with scattered SC-1; indicates long dwell/high deposition. Indicative relief: ~40–120 μm (film stack/compacted fines).
• Reclassify when: After true residue lift, modeled micro-texture or SC>0 persists → evaluate M.02 abrasion fields; if rust-toned dots/pits are evident, consider Th.01.02 grinder spark embed; if oily amber tone, see R.04.03 HVAC oil or R.04.04 kitchen grease.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” removal during classification.

• vs. HVAC aerosol/oil film (R.04.03): HVAC films feel oily, show wetting anomalies; soot is dry, transfers to cloth, with less wetting contrast.
• vs. Kitchen grease (R.04.04): Grease has amber tone, tacky feel, spatter; soot is grey/black, uniform, dry.
• vs. Nicotine/tar (R.04.05): Nicotine shows amber/brown cast and odor; soot is neutral/dark grey to black, odorless/combustion-like.
• vs. Mineral system (Ch.03): Minerals show white/grey rings/runs with crystalline edges; soot lacks crystalline borders and lifts dry.
• vs. Hot-particle peppering (Th.01.02): Hot-particle leaves pits/fused nodules and sometimes rust dots; soot is film-like with no pits.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of particulate texture, wipe windows, deposition gradients; façade context showing traffic/stack sources. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.01.03 Soot / Particulate Pollution Film — Grey–black dry veil with wipe windows on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: dry transfer to cloth, deposition bias to source, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to M.02 if abrasion remains post-lift, or to Th.01.02 if pits/nodules are present; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Condensation / runoff patterns are appearance changes on glass driven by recurrent water paths (dew, HVAC condensation, building runoff, irrigation overspray) that concentrate dissolved soils/minerals and produce rivulet maps, drip legs, curtains, and edge blooms. With prolonged cycling, very shallow micro-texture may form in preferred paths. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Vertical “drip legs” emanating from head frames, mullions, signage, or projection elements; fan-shaped curtains from head to sill.
• Rivulet networks that repeat pane-to-pane based on façade geometry; edge blooms where water pools/dwells at gaskets.
• Under raking: sheen discontinuities along flow lines; where cycling is long-term, low-contrast matte within the path.

• Surface-catch class (MSRT)
• SC-0 for residue films that lift on reveal.
• SC-1 where incipient micro-texture is present inside flow paths (slight tactile interruption, no chip flanks). SC-2 suggests misclassification—evaluate Ch.03.03 mineral etching or M.02 abrasion if present.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Continuous flow lines from a discernible origin (head/drip edge/hardware) to sill; branching rivulets that merge/split; repeating geometry across adjacent lites.
• No chip-flank sparkle (not linear scoring); no fused pits/nodules (not hot particle).
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal incidence and oblique sweep (~60°–120°); use raking to reveal flow edges and matte inside paths. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Most common on outboard (#1) faces; interiors (#4) where condensation is recurrent (pools, natatoriums, chilled beams). Between-pane by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Roof/facade runoffs, misaligned drips, sprinkler overspray, condensation from HVAC diffusers, uninsulated frames, or thermal bridges producing interior condensate trails.

• Assign CAT by visibility at acceptance geometry and MSRT after a reveal patch. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Clear rivulet/drip pattern comprised of residue only; SC-0; mainly angle/raking visible; lifts on reveal patch. Indicative relief: 0–10 μm (optical film).
• CAT-2 (Light): Persistent flow mapping post-reveal with localized SC-1 (incipient micro-texture from cycling); limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area, legible flow curtains at standard distance with consistent SC-1 and low-contrast matte inside paths; indicates long dwell/high frequency. Indicative relief: ~40–120 μm.
• Reclassify when: Distinct white/grey crystalline rims or etched halos dominate → evaluate Ch.03 (mineral deposits/staining/etching); linear swirl/abrasion → M.02 abrasion fields.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Hard-water mineral system (Ch.03): Minerals show crystalline rings/rims and can progress to etch; pure runoff mapping may lack crystals and lifts on reveal.
• vs. Detergent/surfactant film (R.04.01): Detergent presents tool-path streaks/iridescence; runoff follows gravity paths from a structural origin with no wipe geometry.
• vs. Atmospheric corrosion matte (E.01.02): Atmospheric matte is global/non-directional; runoff patterns are directional with clear origins and branching trails.
• vs. Kitchen/HVAC films (R.04.03/04): Those show oily/tacky veils and wetting anomalies; runoff is flow-path specific and often coincident with drip edges or sprinkler arcs.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of flow edges/matte fields; context frames of origins (head/drip edge/sprinkler/diffuser) and multiple adjacent lites to show repeatability. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.01.04 Condensation / Runoff Patterns — Directional rivulet/drip mapping from [origin: head frame / sprinkler / diffuser / hardware] on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: flow lines, curtains, edge blooms; no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to Ch.03 if crystalline rims/etch halos dominate; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Wind-borne sand abrasion is an appearance change on glass caused by air-entrained mineral particulates (silica, feldspar, grit) scouring exposed faces under sustained winds. It presents as directional frosting/haze, micro-pitting, and fine linear incisions concentrated on windward elevations and edge “blast” zones near frames and corners. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Matte/frosted fields with grain-aligned directionality (prevailing wind).
• Heavier strike at leading edges, mullion reveals, parapet-level lites, and near grade in arid sites.
• Under raking: uniform scatter from micro-texture, interspersed with fine, shallow incisions; may show height gradient (stronger low, tapering upward).

• Surface-catch class (MSRT)
• Commonly SC-1 (fine micro-texture) progressing to SC-2 where micro-pits/incipient incisions are present; SC-0 only at earliest film-only stages.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use a polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Directional matte (frosted look) with grain-wise streaking; no oily gloss, no wipe arcs.
• Under oblique sweep, sparkle is absent (not chip-flank sparkle) but catch is tactile where incisions/pits exist.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use low-angle raking to reveal directional micro-texture and localized edge blast. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Predominant on outboard (#1) faces. Between-pane by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Arid/coastal dunes, construction sites with exposed soils, high-wind corridors, sand storms; adjacent abrasive landscaping media or unpaved lots.

• Assign CAT by visibility at acceptance geometry and MSRT after a reveal patch. Depth values are indicative—field measurement not required.
• CAT-2 (Light): Incipient directional haze; SC-1 (micro-texture), minimal standard-view impact; isolated shallow ticks. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Distinct directional frosting legible at standard distance; consistent SC-1 with scattered SC-2 from micro-pits/incisions. Indicative relief: ~40–120 μm.
• CAT-4 (Severe): Wide-area matte/frosted fields and roughened strike zones clearly visible at standard and wide-field views; SC-2 prevalent with micro-pitting. Indicative relief: ~120–300 μm (local maxima can exceed).
• Reclassify when: If fused nodules/peppering or rust-toned dots appear → evaluate Th.01.02 grinder spark embed; if patterns are non-directional milky without catch → consider E.01.02 atmospheric matte; if linear, incised score lines dominate with chip-flank sparkle → evaluate M.01 linear scoring.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Atmospheric corrosion matte (E.01.02): Atmospheric matte is non-directional and edge/rivulet biased; eolian abrasion is directional with prevailing-wind alignment.
• vs. Residue films (R-family): Residues show wipe geometry, wetting anomalies, or odor; eolian abrasion shows grain-aligned scatter, no wipe arcs, and tactile catch at SC-1/2.
• vs. Mineral etching (Ch.03.03): Mineral etch maps drip/ring halos; eolian abrasion forms broad directional fields and edge blast unrelated to water paths.
• vs. Hot particle (Th.01): Hot particle shows discrete pits/fused nodules (pepper); eolian abrasion shows continuous frost with micro-pitting, not fused beads.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of directional micro-texture, edge blast, and height gradient; façade context showing ground conditions/wind exposure. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-1/SC-2, or SC-0 if truly film-only).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.02.01 Wind-Borne Sand Abrasion — Directional frosting with edge blast on surface #___ (windward); post-reveal test patch shows [SC-1/SC-2]; visible at [12/36/72 in] under VIS geometry. Morphology: grain-aligned scatter, micro-pitting/incisions, no wipe arcs, no fused nodules. Classification: CAT-[2/3/4] by visibility and SC-class; reclassify per notes if peppering/nodules or non-directional matte is observed; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Dust-storm micro-pitting is an appearance change on glass caused by high-velocity mineral particulate impacts during dust/sand storm events, producing peppered micro-craters and a matte scatter field. Concentrations track wind exposure, building geometry, and near-grade vortices, often forming edge blast zones and height gradients. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Dense peppering of pinpoint craters (50–300+ μm dia.) in exposed zones; more sparse toward sheltered/lee sides.
• Height gradient: strongest near lower elevations and corners, tapering with height; frame-adjacent intensification.
• Under raking: bright micro-sparkles at crater rims and non-directional matte between impacts; may overlay directional eolian frost (see E.02.01).

• Surface-catch class (MSRT)
• Commonly SC-2 within peppered fields (distinct interruption over crater rims); SC-1 at transition margins; SC-0 only outside impact zones.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use a polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Discrete, random micro-craters (not fused nodules), sometimes with raised rim/chip; no wipe arcs, no oily gloss.
• Under oblique sweep, specular highlights blink at individual pits; between pits, low-contrast frost may be present.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); employ low-angle raking macros to show crater geometry and edge blast density. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Typical on outboard (#1) faces in arid regions or after extreme wind events. Between-pane peppering by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Recent dust/sand storm, construction winds, gust fronts; accumulated grit on sills/frames; reports of abrasive blasting rain.

• Assign CAT by visibility at acceptance geometry and MSRT after a reveal patch. Depth values are indicative—field measurement not required.
• CAT-2 (Light): Sparse micro-pits in bands or corners; SC-1 at margins, SC-2 intermittent; minimal standard-view impact. Indicative relief: ~20–60 μm (pit depth).
• CAT-3 (Moderate): Continuous pepper field legible at standard distance; SC-2 common; matte between pits. Indicative relief: ~60–150 μm typical.
• CAT-4 (Severe): High-density peppering and rough edge blast clearly visible at standard and wide-field, frequent coalesced pits; SC-2 prevalent. Indicative relief: ~150–350+ μm local maxima.
• Reclassify when: If fused metallic nodules/rust dots are observed → evaluate Th.01.02 grinder spark embed; if damage is continuous directional frost with few discrete pits → consider E.02.01 eolian abrasion; if linear incised score lines dominate → M.01 linear scoring.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Hot-particle peppering (Th.01.02): Hot particles show fused metal beads/pits (often rust-toned) and thermal halos; dust-storm pits are mineral impact craters without metallic residues.
• vs. Eolian frosting (E.02.01): Eolian presents directional micro-texture with fewer discrete pits; dust-storm micro-pitting shows random peppering superimposed (often both coexist).
• vs. Stone/seed defects (P.02.03): Factory stones are internal inclusions or polished-out craters with production context; storm pits are surface impacts with exposure mapping.
• vs. Chemical etch (Ch.01/Ch.02/Ch.03.03): Chemical etch yields modeled, non-particulate micro-texture; storm pits are discrete, rimmed craters.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of individual pits, density maps, edge blast zones; façade context documenting windward/lee sides and site exposure. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-1/SC-2) within pepper fields and outside as control.
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.02.02 Dust-Storm Micro-Pitting — Peppered micro-craters with edge blast gradient on surface #___ (windward); post-reveal test patch shows [SC-2 in field / SC-1 at margins]; visible at [12/36/72 in] under VIS geometry. Morphology: random rimmed pits, non-directional peppering, inter-pit matte; no fused nodules. Classification: CAT-[2/3/4] by visibility and SC-class; reclassify per notes if metallic fusion or directional frost predominates; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Algae / biofouling film is an appearance change on glass resulting from microbial colonization (algae, cyanobacteria, biofilms) under persistent moisture and nutrient availability (organics, dust). It presents as green to brown films, strand/filament colonies at gasket/edge zones, and wetting anomalies where biofilm alters surface energy. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Greenish film in shade-damp exposures; brown/olive in sun-exposed, nutrient-rich areas.
• Edge-biased colonies: along gaskets, sealant joints, weeps, and horizontal ledges where water dwells.
• Filamentous/spot clusters; may co-present with runoff patterns (E.01.04) and salt or mineral residues.

• Surface-catch class (MSRT)
• Typically SC-0 (soft biofilm).
• SC-1 localized where entrained grit or repeated wiping created very shallow micro-texture; SC-2 suggests misclassification—check M.02 abrasion fields or Ch.03.03 mineral etch if matte persists post-reveal.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Chromatic film (green/olive/brown), stringy colonies at edges/weep paths, beading/sheeting changes after misting due to biofilm wetting effects.
• No chip-flank sparkle, no fused pits/nodules.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); raking macros to show colony edges, filaments, and wetting contrast. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Common on outboard (#1) in shady, damp zones; can appear on inboard (#4) in natatoriums/greenhouses. Between-pane by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Persistent moisture, overspray/irrigation, blocked weeps, organics deposition (trees, pollen), near landscaping.

• Assign CAT by visibility at acceptance geometry and MSRT after a small reveal patch. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Thin chromatic biofilm; SC-0; angle/raking visible; lifts on reveal patch. Indicative relief: 0–10 μm (optical).
• CAT-2 (Light): Persistent film/colonies with localized SC-1 from grit entrapment or prior wiping; limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area growth clearly legible at standard distance with edge blooms and recurring wetting anomalies; SC-1 scattered. Indicative relief: ~40–120 μm.
• Reclassify when: Post-reveal, if non-directional matte persists without biofilm → evaluate E.01.02 atmospheric matte; if white crystalline rims/etch dominate → Ch.03 mineral system; if linear abrasion remains → M.02.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Algae-like mineral staining (Ch.03.02): Mineral films are inorganic, whitish/grey, with crystalline rims; biofilm is chromatic (green/brown) and organic, often slimy when wet.
• vs. Kitchen/HVAC films (R.04.03/04): Those are oily/amber and track air/grease paths; biofilm tracks moisture dwell and nutrient load.
• vs. Mold on sealants (off-glass): Mold resides on sealant/frames; confirm on-glass presence before classification.
• vs. Coating anomalies (Co-family): Coating issues show color/patchiness on designated coated faces; biofilm responds to reveal and aligns with moisture patterns.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of colonies/filaments, wetting anomalies, edge blooms; context of moisture sources/landscaping/weep details. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.03.01 Algae / Biofouling Film — Green/brown biofilm with edge colonies and wetting anomalies on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: chromatic film, strandy colonies, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to Ch.03 or E.01.02 per persistence/chemistry; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Lichens / moss represent biological colonization on glass under persistent damp/shade with nutrient deposition (dust, organics). They appear as tenacious rough pads (lichens) or small green tufts (moss), commonly edge-biased near gaskets, sealants, weeps, horizontal ledges, and shaded façades. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Lichens: Crustose or foliose discs (1–10+ mm), pale grey/green, matte and rough; often in clusters at edges/ledges.
• Moss: Bright to dark green tufts (1–5+ mm), soft “pile” look, retain moisture; often nestled at frame interfaces.
• May co-present with algal film (E.03.01) and runoff patterns (E.01.04).

• Surface-catch class (MSRT)
• Typically SC-0 (organic mass on surface).
• SC-1 can register adjacent to colonies where grit is embedded or prior abrasive wiping created very shallow micro-texture. SC-2 suggests misclassification—re-evaluate for M.02 abrasion fields or Ch.03.03 mineral etch if matte persists post-reveal.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Discrete, adherent pads/tufts with rough texture and matte finish; may trap soil grains and retain moisture.
• No chip-flank sparkle, no fused pits/nodules; colonies cast tiny shadows at oblique light.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use raking macros to show surface relief and attachment edges. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Common on outboard (#1) shaded/damp zones; rare on inboard (#4) except high-humidity interiors (natatoriums/greenhouses). Between-pane by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Vegetation proximity, irrigation overspray, blocked weeps, persistent shade, organic debris on sills/gaskets.

• Assign CAT by visibility at acceptance geometry and MSRT after a small reveal patch around (not through) a colony. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Sparse, small colonies with SC-0 surroundings; visible mainly in raking/angle; lifts when organic mass is dislodged on test patch. Indicative relief: 0–10 μm (optical film residue only).
• CAT-2 (Light): Multiple colonies/edge clustering with localized SC-1 where grit entrapment created slight micro-texture; limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Broad colonization legible at standard distance (edge belts/ledges), scattered SC-1, persistent wetting anomalies after rinse. Indicative relief: ~40–120 μm (film stack/adjacent micro-texture).
• Reclassify when: Post-reveal, if non-directional substrate matte remains without organics → E.01.02 atmospheric matte; if white crystalline rims/etch present → Ch.03 mineral system; if linear abrasion remains → M.02.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Algae/biofilm (E.03.01): Algae is thin chromatic film; lichens/moss are discrete, raised colonies with physical relief.
• vs. Sealant/mastic smear (R.01.xx): Sealant residue is oily/tacky with stringers; colonies are dry/vegetative and retain moisture when misted.
• vs. Mineral accretions (Ch.03.01/02): Minerals are inorganic, crystalline/white-grey; colonies are green/olive/grey, organic, and compressible.
• vs. Coating anomalies (Co-family): Coating issues are planar/patchy on designated faces; colonies are raised, edge-biased, and respond to reveal.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of colony relief, attachment edges, edge clustering; façade context showing shade/moisture/vegetation. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal patch around the colony, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.03.02 Lichens / Moss (Rough Adhesion) — Discrete rough colonies/tufts at edges/ledges on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: raised pads/tufts, moisture dwell context, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify per notes if inorganic accretions or substrate matte persist; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Tree sap / organic exudate shadow is an appearance change on glass arising from plant resins/exudates (e.g., conifer resin, honeydew, plant gums) that deposit as amber droplets/films and may brown under UV. It presents as tacky amber spots, stringy smears, or browned films with distinct wetting anomalies; after removal, a shadow (tone change) may remain where long dwell + UV altered the near-surface. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Discrete amber beads (0.5–5+ mm), tear-runs, or dragged stringers from attempted wipes; can bloom brown with sun exposure.
• Edge pooling at heads/sills below overhanging trees/vines; patterns repeat below canopy drip lines.
• Post-lift “shadow”: slight tone/shine shift or wetting contrast persists where resin sat for long periods.

• Surface-catch class (MSRT)
• SC-0 for fresh/tacky residue (film on top).
• SC-1 where long dwell/UV leaves very shallow micro-texture or resin entraps fine grit; SC-2 is atypical—if present after true residue lift, reassess for Ch.01/Ch.02 chemical etch or Ch.03.03 mineral etching.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Amber → brown droplets/films; tacky feel on contact; stringers/“spider silk” threads when smeared.
• Wetting anomalies (beading/sheeting contrast) reappear after a light mist over the region.
• No chip-flank sparkle, no fused pits/nodules.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use raking macros to show resin meniscus, stringers, and shadow boundary after reveal. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Most common on outboard (#1) faces under canopies, near landscaping or parking. Between-pane by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Overhanging trees (conifers/common sap producers), seasonal exudation, insect honeydew, landscaping maintenance; corroborating deposits on frames/sills.

• Assign CAT by visibility at acceptance geometry and MSRT after a true residue lift test on a contained patch. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Discrete amber droplets/film; SC-0; angle/raking visible; lifts on reveal test patch without shadow. Indicative relief: 0–10 μm (optical film).
• CAT-2 (Light): Persistent “shadow” or slight wetting contrast after residue lift with localized SC-1; limited standard-view impact. Indicative relief: ~10–40 μm (incipient micro-texture/organic interaction).
• CAT-3 (Moderate): Wide-area browned film/shadowing legible at standard distance, scattered SC-1; indicates long dwell + UV or repeated deposition. Indicative relief: ~40–120 μm.
• Reclassify when: After true residue removal, if modeled substrate micro-texture persists (non-directional matte with SC-1/2) → evaluate E.01.02 atmospheric matte or Ch.02 alkaline attack depending on context; if rings/etched halos consistent with mineral etch present → Ch.03.03; if linear abrasion from cleaning attempts → M.02 abrasion fields.
• CAT-5 (by condition/location): Between-pane by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Kitchen grease/HVAC oil (R.04.03/04): Those are oily/amber veils tracing air paths; sap shows discrete beads/stringers and aligns with tree drip geometry.
• vs. PVC plasticizer smear (R.05.02): PVC films are oily amber with strong wetting anomalies along component contact; sap is tacky, often with meniscus beads and seasonal context.
• vs. Mineral staining/etch (Ch.03): Mineral halos are white/grey crystalline-edged; sap amber/brown, sometimes leaves color shadow after lift without crystalline rims.
• vs. Algae/biofilm (E.03.01): Biofilm is thin, chromatic (green/brown) and spreads; sap is beaded/stringy and tacky.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of droplet meniscus, stringers, and post-lift shadow boundary; context frames showing canopy/drip line. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch and true residue lift, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.03.03 Tree Sap / Organic Exudate Shadow — Amber droplets/stringers with post-lift shadow on surface #___ beneath [tree/canopy]; post-reveal test patch shows [SC-0 residue / SC-1 shadow]; visible at [12/36/72 in] under VIS geometry. Morphology: tacky amber beads, UV-browned film, wetting anomaly, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify per notes if substrate etch or mineral halos dominate; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Avian residue acid shadow is an appearance change on glass produced by bird droppings (mixture of uric acid/urates, water, organics) that deposit as discrete splats and may bleach or dull the underlying glass after removal, leaving a color/shine “shadow.” High dwell time, sun/heat, and repeated incidents increase the likelihood of near-surface alteration. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Discrete splats (10–50+ mm) with radial feathering and white urate crust; occasionally mixed brown/green organics.
• Run-legs from the splat on sloped panes or after dew; edge pooling at micro-texture inside the splat area.
• After residue lift: pale “ghost” or shadow area (reduced gloss, slight color shift).

• Surface-catch class (MSRT)
• SC-0 for fresh/dry crust (residue on top).
• SC-1 localized if long dwell + heat produced very shallow micro-texture or trapped grit; SC-2 is atypical—if present after true residue lift, reassess for Ch.01 (acid attack) or Ch.03.03 (mineral etching).
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use a polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• White crystalline/opaque urate crust with radial feathers and splat edge ring; may show brown/green organic center.
• Post-lift shadow: subtle loss of specular “snap” or color/shine change confined to the splat footprint.
• No chip-flank sparkle, no fused nodules.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal incidence and oblique sweep (~60°–120°); use raking macros to show splat geometry, edge ring, and post-lift shadow boundary. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Common on outboard (#1) horizontal/near-horizontal surfaces (canopies, sills, skylights), signage ledges. Between-pane by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Avian perches above (sign letters, mullion caps), nesting/roost zones, overhangs; repetition beneath common perch points; co-evidence on frames/sills.

• Assign CAT by visibility at acceptance geometry and MSRT after a true residue lift test on a contained patch. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Discrete splat residues that fully lift on reveal; SC-0; visible mainly at angle/raking. Indicative relief: 0–10 μm (optical film/crust only).
• CAT-2 (Light): Post-lift shadow (minor gloss/tone change) with localized SC-1; limited standard-view impact. Indicative relief: ~10–40 μm (incipient near-surface change).
• CAT-3 (Moderate): Multiple/overlapping splat shadows legible at standard distance, scattered SC-1; indicates long dwell, heat exposure, or repeated incidents. Indicative relief: ~40–120 μm
• Reclassify when: After true residue removal, if modeled matte persists with SC-1/2 beyond the splat footprint → consider Ch.01 (acid attack); if crystalline ring/etch halo consistent with hard-water dominates → Ch.03.03; if linear abrasion from cleaning attempts remains → M.02 abrasion fields.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Mineral staining/etch (Ch.03): Minerals present white/grey crystalline rings with run mapping; avian shows distinct splat morphology with urate crust and radial feathering.
• vs. Organic sap (E.03.03): Sap is amber/tacky with stringers; avian is white/grey crust with organic center and splat geometry.
• vs. Detergent/surfactant film (R.04.01): Detergent shows wipe streaks/iridescence; avian shows radial splash, ring, and localized post-lift shadow.
• vs. Atmospheric matte (E.01.02): Atmospheric is global/non-directional; avian is localized to splat footprints under perches.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of splat edge, feathering, post-lift shadow boundary; context frames showing perch/nesting features above. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch and true residue lift, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.03.04 Avian Residue Acid Shadow — Discrete splat with urate crust on surface #___ beneath [perch/letter/cap]; post-reveal test patch shows [SC-0 residue / SC-1 shadow]; visible at [12/36/72 in] under VIS geometry. Morphology: radial feathering, edge ring, localized post-lift shadow, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify per notes if broader acid etch or mineral halos dominate; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Recurring drip/run staining is an appearance change on glass caused by repeated gravity-driven moisture paths that carry soils/minerals/organics from upstream features (caps, signage letters, flashings, parapets, shading fins). It presents as vertical “drip legs,” fan-shaped runs, or curtains that repeat at the same height across adjacent lites beneath the same source detail. With extended cycling, very shallow micro-texture may form within the flow paths. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Parallel drip legs or fan runs that start at a common elevation (beneath a continuous head/cap or line of letters) and extend toward the sill.
• Density/width increases beneath joints or fasteners where leakage starts; pane-to-pane repeatability is common.
• Under raking: sheen change along leg edges; in long-dwell cases, a low-contrast matte appears inside the path.

• Surface-catch class (MSRT)
• SC-0 where contamination is residual film only and lifts on reveal.
• SC-1 where incipient micro-texture exists from cyclic deposition/soils. SC-2 suggests misclassification—consider Ch.03.03 mineral etching or M.02 abrasion.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use a polymer stylus if a functional coating is suspected. MSRT supports classification only
• Visual signature
• Directional, gravity-consistent flow mapping with a discernible origin line (elevation) and repetition on adjacent lites.
• No chip-flank sparkle (not scoring); no fused pits (not hot particle).
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use raking to reveal leg edges and interior matte. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Typically outboard (#1); between-pane by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Architectural drip sources visible above (parapet caps, letterforms, shading devices, leaking joints), irrigation overspray from height, or condensate rails.

• Assign CAT by visibility at acceptance geometry and MSRT after a reveal patch. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Legible drip runs comprised of residue film only; SC-0; mainly angle/raking visible; lifts on reveal. Indicative relief: 0–10 μm.
• CAT-2 (Light): Persistent runs post-reveal with localized SC-1 (incipient micro-texture); limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area run curtains legible at standard distance with consistent SC-1 and interior low-contrast matte; indicates long dwell/high frequency. Indicative relief: ~40–120 μm.
• Reclassify when: White/grey crystalline rims, ringed edges, or etched halos dominate → Ch.03 Mineral system (Deposits/Staining/Etching). If linear swirl from cleaning attempts persists → M.02 Abrasion fields.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Condensation/runoff (E.01.04 general): E.01.04 covers the general phenomenon; E.04.01 is used when repeatable source-specific runs from architectural details are the dominant presentation (spec use case).
• vs. Hard-water mineral system (Ch.03): Minerals exhibit crystalline rims/etch; recurring drip runs may be film-only—verify with reveal + MSRT.
• vs. Detergent/surfactant film (R.04.01): Detergent shows tool-path streaks/iridescence; recurring runs follow gravity from a common elevation with no wipe geometry.
• vs. Atmospheric matte (E.01.02): Atmospheric is global/non-directional; recurring runs are directional, repeat by pane, and tie to visible sources.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of leg edges/interior matte; context frames of source detail and adjacent panes showing height repetition. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.04.01 Recurring Drip / Run Staining Pattern — Directional drip legs/fan runs repeating at [elevation] beneath [source detail] on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: gravity-consistent flow, pane-to-pane repetition, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to Ch.03 if crystalline rims/etch dominate; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Thermal bridging condensation patterning is an appearance change on glass caused by recurrent condensation along thermal bridges (metal mullions, anchors, frame receptors, spandrels, poorly insulated interfaces) and isotherm lines. Moisture cycles deposit/redistribute soils or dissolved minerals, yielding ghosted grids, stripes, ovals, or edge blooms that mirror the underlying framing or cold-spot geometry. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Interior (#4) winter cases: Pale bands/rectangles tracing mullion locations, pane edges, or spandrel transitions; strongest during/after cold snaps or high indoor humidity.
• Exterior (#1) summer cases: Ghosted ovals/bands at thermal bridges (shadow boxes, anchors) where nighttime cooling and morning dew repeat.
• Edge blooms or narrow outlines following setting blocks/gaskets; repeatable pane-to-pane at identical structural locations.

• Surface-catch class (MSRT)
• SC-0 for film-only residues that lift on reveal.
• SC-1 localized where long dwell/cycling leaves very shallow micro-texture inside the condensation footprint; SC-2 suggests misclassification—consider Ch.03.03 mineral etching or M.02 abrasion if present.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Geometry-locked mapping (grids/stripes/ovals) that matches framing/anchors/spandrel boundaries; uniform tone shift rather than linear scoring; no chip-flank sparkle; no pits.
• Under raking: sheen discontinuity along pattern edges; interior cases often show breathing with HVAC cycles.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use raking to reveal pattern edges and any interior matte. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Interior (#4) presentations are common in cold-weather condensation; exterior (#1) in dew cycles. Between-pane mapping on #2/#3 via parallax → CAT-5 by location.
• Mechanism cue (context)
• Thermal bridges (continuous aluminum, poorly broken frames), high indoor RH, HVAC setbacks, night sky cooling, shadow box/spandrel transitions, edge spacer influence.

• Assign CAT by visibility at acceptance geometry and MSRT after a reveal patch. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Ghosted grid/oval comprised of residue film only; SC-0; mainly angle/raking visible; lifts on reveal. Indicative relief: 0–10 μm.
• CAT-2 (Light): Persistent geometry post-reveal with localized SC-1 (incipient micro-texture from cycling); limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area pane-to-pane pattern legible at standard distance with consistent SC-1; indicates long dwell/high frequency cycles. Indicative relief: ~40–120 μm.
• Reclassify when: Crystalline rims/etched halos dominate (rings/runs) → Ch.03 Mineral system; linear wipes/iridescence → R.04.01 Detergent/surfactant film; directional frosting/pits → E.02 eolian / dust-storm; pits/fused nodules → Th.01 hot particle.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Ch.03 mineral system: Minerals show white/grey crystalline rims/etched run halos; thermal-bridge mapping is geometry-locked to framing/anchors and may lack crystalline borders.
• vs. Atmospheric matte (E.01.02): Atmospheric is global/non-directional; thermal-bridging is geometric and repeatable.
• vs. Coating anomalies (Co-family): Coating patchiness is often on designated coated faces and not tied to thermal geometry; thermal patterns correlate with substrate temperature fields.
• vs. Residues from cleaning (R.04.01/02): Cleaning films show tool-path streaks/iridescence; thermal patterns follow isotherms, not wipe trajectories.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of pattern edges; context frames of mullion/spandrel layout and adjacent panes to show repeatability. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.04.02 Thermal Bridging Condensation Patterning — Geometry-locked ghosting aligned with [mullions/spandrel/anchors/edges] on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: grid/stripe/oval mapping of cold-spot isotherms, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to Ch.03 if crystalline rims/etch dominate, or to R.04.01 if wipe/iridescence patterns are present; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Curtain wall runoff staining (adjacent materials interactions) is an appearance change on glass caused by moisture transporting constituents from neighboring materials—sealants, gaskets, metals, masonry, timber, coatings—onto the glass surface during rain/dew/condensation events. It presents as vertical run curtains, bay-repeat streaks, and tone-specific veils (e.g., brown tannins, orange/rust oxides, black bitumen, siloxane halos). Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Bay-to-bay repetition: runs align beneath consistent material interfaces (spandrel sill, parapet cap, masonry copings, signage rails).
• Color cues by source: orange-brown below weathering steel or rusty hardware; tea-brown below timber/tannins; black below bitumen/roof tars; dark grey below zinc/galvanized wash; clear-to-greasy halos adjacent to silicone/EPDM.
• Edge blooms where water dwells at gaskets or sealant laps; joint-intensified bands.

• Surface-catch class (MSRT)
• SC-0 where deposits are film-only and lift on reveal.
• SC-1 in zones of long-cycle deposition producing very shallow micro-texture; SC-2 suggests misclassification—check Ch.03.03 mineral etching or M.02 abrasion.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use a polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Vertical curtains / drip legs tied to particular upstream materials; tonal cast reflects source chemistry; no chip-flank sparkle (not scoring); no fused pits (not hot particle).
• In raking: sheen discontinuities along run edges; sometimes wetting anomalies near elastomers or silicone bleed.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use raking to reveal edge definition, tone, and any interior matte. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Typically presents on outboard (#1) faces beneath caps, copings, spandrels, masonry, timber, roofing interfaces. Between-pane mapping by parallax on #2/#3 → CAT-5 by location.
• Mechanism cue (context)
• Presence of corroding metals, tannin-rich timber, bitumen/tar, silicones/EPDM, masonry wash above flow paths; staining on frames/sills corroborates source.

• Assign CAT by visibility at acceptance geometry and MSRT after a reveal patch. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Tone-specific run curtains comprised of residue only; SC-0; primarily angle/raking visible; lifts on reveal. Indicative relief: 0–10 μm.
• CAT-2 (Light): Persistent toned runs post-reveal with localized SC-1 (incipient micro-texture); limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area, bay-repeat staining legible at standard distance with consistent SC-1 inside curtains; indicates long dwell/high frequency. Indicative relief: ~40–120 μm.
• Reclassify when: White/grey crystalline rims or etched halos dominate → Ch.03 Mineral system; linear wipe/iridescence → R.04.01 Detergent/surfactant film; metallic speck/pits → Th.01.02 grinder spark embed.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. E.04.01 recurring drip/run (generic): E.04.03 is used when source chemistry imparts distinctive tone/halo attributable to specific adjacent materials.
• vs. Mineral system (Ch.03): Minerals show crystalline ring/rims and may etch; runoff staining from materials can be chromatic (tannin, oxide, bitumen) and film-dominant—verify with reveal + MSRT.
• vs. Coating anomalies (Co-family): Coating issues are planar/patchy on designated faces, not gravity-driven from upstream materials.
• vs. HVAC/kitchen films (R.04.03/04): Those track air paths and feel oily/tacky; material runoff follows gravity, has source-specific color, and repeats bay-to-bay.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of run edges, tonal character, and interior matte; context frames showing upstream materials and pane-to-pane repetition. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.04.03 Curtain Wall Runoff Staining (Adjacent Materials Interactions) — Toned run curtains beneath [material: weathering steel / timber / bitumen / silicone / masonry] on surface #___; post-reveal test patch shows [SC-0/SC-1]; visible at [12/36/72 in] under VIS geometry. Morphology: bay-repeat vertical runs, source-specific color/halo, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to Ch.03 if crystalline rims/etch dominate, or to R.04.01 if wipe/iridescence patterns are present; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

UV-induced browning/yellowing of residues is an appearance change on glass caused by photo-oxidation and polymerization within organic surface films (detergent remnants, maintenance additives, kitchen/HVAC aerosols, tree resins/honeydew carryover), producing a persistent amber/yellow veil and wetting anomalies. With prolonged exposure, very shallow micro-texture may develop beneath the film. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Warm amber/yellow cast most apparent in reflections or when viewed across light-to-dark backgrounds; stronger on sun-exposed elevations.
• Patchy or uniform veils following wipe paths, spray cones, or airflow routes (interiors near kitchens/HVAC, exteriors near exhausts).
• Wetting contrast: areas bead/sheet differently due to altered surface energy.

• Surface-catch class (MSRT)
• Typically SC-0 (film on top).
• Local SC-1 where long dwell + UV produced incipient substrate micro-texture or where grit was trapped in the film; SC-2 suggests misclassification—consider M.02 abrasion fields or Ch.03.03 mineral etching if matte persists after true film lift.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Amber/yellow veil with wipe geometry or air-path mapping; sometimes edges of patches appear slightly darker.
• No chip-flank sparkle, no discrete pits/fused nodules. After misting, wetting anomalies outline the film.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use raking to reveal film thickness variations and edge outlines. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Occurs on outboard (#1) near exhaust/organics and inboard (#4) near kitchens/HVAC. Between-pane identification on #2/#3 via parallax → CAT-5 by location.
• Mechanism cue (context)
• History of detergent/additive use, fragrance or surfactant residues, cooking aerosols, HVAC carryover, or nearby organics (sap/honeydew) with sun exposure.

• Assign CAT by visibility at acceptance geometry and MSRT after a true film-lift test. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Thin amber veil; SC-0; angle/raking visible; clears fully on reveal patch. Indicative relief: 0–10 μm (optical film only).
• CAT-2 (Light): Persistent amber cast post-reveal with localized SC-1 (incipient substrate change); limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area discoloration legible at standard distance, scattered SC-1; indicates long dwell/high UV dose or repeated deposition. Indicative relief: ~40–120 μm.
• Reclassify when: If oily/neutral film without yellowing dominates → R.04.03 HVAC oil or R.04.04 kitchen grease; if white/grey crystalline rims/etch dominate → Ch.03 mineral system; if linear swirls/webs persist → M.02 abrasion fields.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Nicotine/tar film (R.04.05): Nicotine is brown/amber with odor and interior air-path mapping; UV browning may present exterior as well and aligns with sun exposure and prior organic residues.
• vs. Tree sap shadow (E.03.03): Sap shows discrete beads/stringers and post-lift shadow; UV-browned films are more uniform/patchy with wipe or airflow geometry.
• vs. Coating anomalies (Co-family): Coating issues are planar/patchy on designated coated faces and persist independent of cleaning history; browned films respond to film-lift testing and track usage/exposure.
• vs. Atmospheric matte (E.01.02): Atmospheric matte is non-directional, often edge/rivulet-biased; browned films show wipe/air-path mapping and color shift.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of film edges, color cast, and wetting anomalies; context frames showing sun-exposed elevation or source zones (kitchen/HVAC/exhaust). Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch and true film-lift, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.05.01 UV-Induced Browning / Yellowing of Residues — Amber/yellow veil with wipe/air-path geometry on surface #___; post-reveal test patch shows [SC-0 film / SC-1 localized]; visible at [12/36/72 in] under VIS geometry. Morphology: photo-browned organic film, wetting anomalies, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to R.04.03/R.04.04 (oily films), Ch.03 (mineral), or M.02 (abrasion) as indicated; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

Oxidation darkening of films is an appearance change on glass caused by oxidative aging of organic surface residues (maintenance detergents/additives, HVAC/kitchen aerosols, traffic-related organics) and/or particulate entrainment (soot/oxyde fines) within those films. It presents as a neutral grey to brown dark veil, often patchy and aligned with wipe paths or airflow cones, with wetting anomalies at boundaries. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Grey→brown dark cast, stronger on high-UV / ozone / pollutant exposures or near traffic/exhaust.
• Patch maps following squeegee strokes, spray cones, return-air vectors, or range-hood plumes.
• Boundary edges show bead/sheet contrast when misted due to altered surface energy.

• Surface-catch class (MSRT)
• Generally SC-0 (aged film on top).
• Local SC-1 where long dwell entrained grit or led to incipient substrate micro-texture; SC-2 suggests misclassification—evaluate M.02 abrasion fields or Ch.03.03 mineral etching if matte persists after true film lift.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.
• Visual signature
• Neutral-to-warm dark veil, often non-uniform; no chip-flank sparkle, no discrete pits.
• Wipe/air-path geometry is common; edges appear harder/darker in raking.
• Viewing / lighting
• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°–120°); use raking to reveal film thickness and edge outlines. Record distances/angles in-frame.
• Location / access
• Record pane ID and surface numbering (#1–#4; laminate-internal). Seen on outboard (#1) near roadways/exhausts and inboard (#4) near kitchens/HVAC. Between-pane detection on #2/#3 via parallax → CAT-5 by location.
• Mechanism cue (context)
• History of detergent/additive stacking, infrequent true rinsing, HVAC carryover, cooking aerosols, diesel corridors; darker accumulation on windward or airflow sides.

• Assign CAT by visibility at acceptance geometry and MSRT after a true film-lift test. Depth values are indicative—field measurement not required.
• CAT-1 (Benign / non-relief): Thin dark veil; SC-0; angle/raking visible; clears fully on reveal patch. Indicative relief: 0–10 μm (optical film only).
• CAT-2 (Light): Persistent dark cast post-reveal with localized SC-1 (incipient substrate change or grit-imprinted micro-texture); limited standard-view impact. Indicative relief: ~10–40 μm.
• CAT-3 (Moderate): Wide-area darkening legible at standard distance, scattered SC-1; indicates long dwell/re-application cycles and oxidative aging. Indicative relief: ~40–120 μm.
• Reclassify when: Amber/yellow hue dominates tied to UV → consider E.05.01 UV-browning; oily neutral film with strong wetting anomalies → R.04.03 HVAC oil / R.04.04 kitchen grease; white/grey crystalline rims/etch → Ch.03 mineral system; linear swirls/webs → M.02 abrasion fields.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.
• CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Soot/particulate film (E.01.03): Soot is dry/transferable and often black; oxidation-darkened films are bound, show wipe geometry, and can be brown/grey.
• vs. UV-browning (E.05.01): UV-browning trends amber/yellow; oxidation darkening trends neutral grey/brown, often pollutant-associated.
• vs. Nicotine/tar (R.04.05): Nicotine is amber/brown with odor and interior airflow mapping; oxidation darkening commonly includes exterior pollutant capture signatures.
• vs. Coating anomalies (Co-family): Coating issues are planar/patchy on designated faces and are independent of wipe/airflow geometry; films respond to film-lift testing.

1. Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of film edges, color/density variations, and wetting anomalies; context frames of traffic/exhaust/HVAC/kitchen zones. Record distance/angle in-frame.
2. MSRT result (substrate): After a small reveal test patch and true film-lift, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
3. Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
4. Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

E.05.02 Oxidation Darkening of Films — Grey→brown aged organic film with wipe/airflow geometry on surface #___; post-reveal test patch shows [SC-0 film / SC-1 localized]; visible at [12/36/72 in] under VIS geometry. Morphology: oxidized dark veil, wetting anomalies, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to E.05.01 (UV-browning), R.04.03/04 (oily films), Ch.03 (mineral), or M.02 (abrasion) as indicated; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.