File: mail-parse.el.html
This file contains wrapper functions for a wide range of mail parsing functions. The idea is that there are low-level libraries that implement according to various specs (RFC2231, DRUMS, USEFOR), but that programmers that want to parse some header (say, Content-Type) will want to use the latest spec.
So while each low-level library (rfc2231.el, for instance) decodes faithfully according to that (proposed) standard, this library is the interface library. If some later RFC supersedes RFC2231, one would just have to write a new low-level library, adjust the aliases in this library, and the users and programmers won't notice any changes.