Float glass with an absorbent or reflecting layer — including low-emissivity (low-e) coatings applied before the glass is otherwise worked — classifies under 700510, provided it is non-wired. The coating must be applied to the glass in sheet form; if the glass is subsequently cut to shape, tempered, or laminated, it moves to a different heading such as 7007.

Yes. AD/CVD orders have been issued on certain flat glass products from specific countries. The scope of each order is defined at the tariff-line and product-specification level, so importers should check the current CBP and Commerce Department order lists against the specific subheading, product description, and country of origin before entry.