The ANSI standard usage of ANSI standard refers to any practice which is typical or broadly done. It's most appropriately applied to things that everyone does that are not quite regulation. For example: ANSI standard shaking of a laser printer cartridge to get extra life from it, or the ANSI standard word tripling in names of usenet alt groups.
This usage derives from the American National Standards Institute. ANSI, along with the International Organization for Standards (ISO), standardized the C programming language (see K&R, Classic C), and promulgates many other important software standards.