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.

Version: unspecified
Severity: enhancement