A defined condition that sends a glass assessment or treatment decision to a manufacturer, engineer, conservator, glazier, laboratory, safety specialist, or other qualified party.

GlassRenu · Educational illustration
Meaning and boundaries
Referral is not failure; it recognizes when a question exceeds the technician's evidence, tools, authority, or scope.
Why it matters in glass restoration
It protects customers and technicians while making unknown or specialty conditions actionable.
Related terms
References
- U.S. National Park Service — Preservation Matters: Stained Glass
Publisher’s original source - U.S. General Services Administration — Cleaning Historic Masonry
Publisher’s original source - National Glass Association — GANA Glazing Manual, 2022 edition
Publisher’s original source - National Institute of Standards and Technology — Fractography of Ceramics and Glasses, 3rd edition
Publisher’s original source - Vitro Architectural Glass — Glass Cleaning Recommendations
Publisher’s original source