"Critical use and line sealer maskant" means a temporary coating, not covered under other maskant categories, used to protect selected areas of aerospace parts from:
strong acid or alkaline solutions such as those used in anodizing, plating, chemical milling, and processing of magnesium, titanium, or high strength steel;
high-precision aluminum chemical milling of deep cuts; and
aluminum chemical milling of complex shapes.
Materials used for repairs or to bridge gaps left by scribing operations (i.e., line sealer) are also included in this definition.
Ill. Admin. Code tit. 35, § 211.1567