Architectural glass products used in commercial construction applications often incorporate multiple lites of glass with different colors, thicknesses, strength, coatings and other surface and edge treatments. The National Glass Association (NGA) recommends the terminology and practices for describing the construction of architectural glass products to be used in windows, doors, skylights, window walls and curtain walls contained within this document. The original version of this document was approved and published in 2007. This version of the document was updated and published in April 2022.