In accordance with Google's suggestion to use or not use nofollow depending on trustworthiness of the user or edit ( http://support.google.com/webmasters/bin/answer.py?hl=en&answer=96569 ), this is a proposal to add an option (turned on or off by a new configuration setting) to apply nofollow only to external links added in revisions marked unpatrolled.
Is there any reason why this shouldn't be implemented as a core feature? I'm thinking, a boolean el_patrolled field should be added to externallinks. The value will be 1 if (a) the URL was added by an autoconfirmed user, or (b) the URL was added by a newbie/anon, but that URL was already in the table as patrolled on another page. Otherwise, the value will be 0, and nofollow will apply to the link.
The value will be switched to 1 as soon as any page is patrolled that contains that URL, and then nofollow will NOT apply to that link anymore. I suppose caches would need to be cleared accordingly.
I don't think the spam whitelist should be used in determining whether nofollow will be applied to a link, because even whitelisted domains are susceptible to being used for spamming. E.g., a person can link to a spammy page he added to a mostly legitimate website. Right now, nofollow is generally used for all external links (since $wgNoFollowLinks defaults to true) so this would still be a significant improvement in the precision of this anti-spam method.
Version: 1.21.x
Severity: enhancement