Last modified: 2009-02-06 21:00:13 UTC
The functions of the username blacklist have been merged into the title blacklist (see r38636). The username blacklist doesn't have full regex support (it can't do regex like "(.)\1{4}"), it has sloppier input and output, has no global equivalent, and can cause performance issues if the regex is too complex (see <http://lists.wikimedia.org/pipermail/wikitech-l/2008-July/038794.html>). No real disadvantages to deprecating the UsernameBlacklist by marking it obsolete.
On WMF wikis, all the username blacklist entries have been moved to the title blacklist using <newaccountonly>.
Done in r46938
