We’re trying to fight WikiSpam, here.
We’re using a Captcha to protect this wiki: Oddmuse:QuestionAsker Extension asks editors for a password and records the fact that you answered correctly in a cookie. Since we’re fighting semi-automated spambots, the password doesn’t have to be hard to find, just not immediately obvious. On 2021-07-22 the name of the cookie was changed so you must all answer the question again, and the password itself was also changed is on the page that’s mentioned by not linked by the prompt (but linked from this page). If you’re having difficulties, send me an email (which also implies a sequence of links to follow, starting at Alex Schroeder).
The BannedContent page prevents pages from being saved if they contain URLs matching one of the regular expressions. You can do this manually, or you can write the regular expression right after you rolled back a page, if you are an admin. There, you’ll see the URLs that got rolled back and based on them you can probably write a good regular expression.
The BannedRegexps page is harsher: the regular expressions it lists are entirely forbidden, no matter where they occur on the page (not just URLs).
The BannedHosts page lists regular expressions matching IP numbers that are banned from editing. This is mostly just useful if people keep using their IP numbers. Sometimes we ban entire ranges. You can do this manually (using whois on the IP number), or you can use the proposals of the Oddmuse:Ban Contributors Extension extension.
Note that all the banning actions only prevent page editing. Page reading is not affected.