Is there such a thing as POSIX-compliant argument descriptions? I know POSIX specifies some things about the format of options, but I didn't realize there was a formalized option description language.
http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_...
This is actually how Docopt happened (Vladimir Keleshev mentioned it in the PyCon UK 2012 talk).