Steve Summit wrote:
[apologies if this is an old suggestion]
We're seeing a spammer who is persistently vandalizing multiple pages with a certain URL. The URL is on the blacklist, so the spammer is now just spelling it out, without any hotlink markup.
See [[Wikipedia:Administrators' noticeboard/Incidents#Ref desk spam]], See [[Wikipedia:Administrators' noticeboard/Incidents#Anontalk spammer]], and [[Wikipedia:Village pump (technical)#Making various types of spam/vandalism that little bit more difficult]].
I realize there's an infinite-regress cat-and-mouse game here, of which a "plaintext" link blacklist implementation is just one more step, but it seems it might be an appropriate next step.
(I have no idea what it would require implementationally, however.)
There're some regex that apply to all page content, not just URLs. They're sporadically used (eg. the 09 F9 11... key, see [[Wikipedia:Keyspam]]) but can only be changed by sysadmins. It has been requested by Vyznev on irc soon after your post and it's now bug 14544.