Similar to https://phabricator.wikimedia.org/T140986, the bzr and cvs schemes should be valid.
* bzr://archonproject.bzr.sourceforge.net/bzrroot/archonproject https://www.wikidata.org/wiki/Q4787330
* cvs://pserver:anonymous@cvs.delorie.com:/cvs/djgpp == :pserver:anonymous@cvs.delorie.com:/cvs/djgpp https://www.wikidata.org/wiki/Q780172
* cvs://pserver:cvsanon@cvs.maptools.org:/cvs/maptools/cvsroot == :pserver:cvsanon@cvs.maptools.org:/cvs/maptools/cvsroot https://www.wikidata.org/wiki/Q1017110
* cvs://pserver:anonymous@steghide.cvs.sourceforge.net:/cvsroot/ == :pserver:anonymous@steghide.cvs.sourceforge.net:/cvsroot/ https://www.wikidata.org/wiki/Q3498040
* (see more with http://tinyurl.com/z62jae6)
The CVS case is interesting because the argument provided to the cvs command is not a URL, which prompted a discussion ( https://www.wikidata.org/wiki/Wikidata_talk:WikiProject_Informatics/FLOSS#CVS_:pserver:_repositories_are_not_URLs ). It turns out there is a cvs scheme described at http://www.iana.org/assignments/uri-schemes/prov/cvs and it could be used instead of the :pserver: notation.