Hallo, Platonides,
Du meintest am 05.12.09:
Install http://www.mediawiki.org/wiki/Extension:TitleBlacklist It allows you to set words that cannot appear in page titles, and also words that are not allowed in account names.
Seems to work as desired - thank you!
I've taken
http://de.wikiversity.org/wiki/MediaWiki:Titleblacklist
as a template, (the last definitions may do the job). And there I found "<newaccountonly>" (and testet it): works well for/ against my drug spammer.
Viele Gruesse! Helmut