It could be nice to be able to factor out regular expressions and give them a display name and description. This would enable a API designer to create his own “types” for URI and query parameters. It would also lead to better documentation, since you don’t have to repeat how a given regular expression acts in every description. It would also make it possible to easily include a lot of common regular expression types like: URI, e-mail, Data URI, ISO8601 date, JS identifier, etc.
What do you think?