The author doesn't believe that rel=“nofollow” is a suitable mechanism to stop wiki spam: Since there will always be some sites that don't use it, it will remain economical for spammers to spam all wikis, even if many of them use rel=“nofollow”. Since there is no economic penalty for useless spam, it's just cheaper to spam all wikis instead of checking.

Nevertheless, rel=“nofollow” is used for some links on Oddmuse wikis: For example, there are several links on the RecentChanges page linking to different views of the list of changes: More or less days, with our without major changes, and so on. Since it makes no sense for search engines to retrieve and index these alternate views, these links use rel=“nofollow”.