The spam blacklist is a control mechanism that prevents an external link from being added to any page when the URL matches regex rules listed at the local or global blacklist, or belongs to a site listed at Special:BlockedExternalDomains. These lists mostly contain spam sites, but also include URL redirection services (which could otherwise be used to bypass blacklisting),^[1] some sites which are persistently abused for shock effects, and some sites which have been added after independent consensus.^[2]

Specific links can be allowed by overruling the blacklisted links through addition to MediaWiki:Spam-whitelist.

The spam blacklist is supported by MediaWiki's SpamBlacklist and AbuseFilter extensions.

MediaWiki:Spam-blacklist is a localized version of m:Spam blacklist, a similar blacklist that affects all Wikimedia Foundation projects. Additions to the local spam blacklist will only affect the English-language edition of Wikipedia, not other projects. Blacklisting requests may be made at MediaWiki talk:Spam-blacklist. However, blacklisting a URL should be used as a last resort against spammers. You should consider the following before requesting that a URL be blacklisted:

• Can protection solve the problem? If so, please make a request at Wikipedia:Requests for page protection.
• Will blocking a single user solve the problem? If you have given appropriate warnings to a spammer, you should report them on Wikipedia:Administrator intervention against vandalism, where they can be blocked by an administrator. Open proxies used to spam should be reported to Wikipedia:Administrator intervention against vandalism or Wikipedia:WikiProject Open proxies so that they can be blocked.
• Will blocking a small number of users for a short time to allow conversation help?

Note that the blacklist only affects live links. Most non-clickable URLs (such as those contained within a nowiki tag) are not affected. However, URLs in edit summaries are affected.

Compelling evidence of a problem should be given when requesting a page to be listed (preferably by giving diffs).

• Proposed additions – Use this section to request additions.
• Troubleshooting and problems – Use this section to report problems with the blacklist. This is not the section to request links to be removed!
• Discussion – Use this section for any other discussion involving the blacklist.

When requesting that a URL be delisted, you should give compelling evidence as to why it should be delisted. Cases of this could include (but are not limited to) hijacked domains being returned to their rightful owner or a site with content that violates copyrights cleaning up their act.

Relevant links:

• Proposed removals – Use this section to request that links be removed from the spam blacklist.
• MediaWiki talk:Spam-whitelist – Use this page to request that specific pages be whitelisted, while keeping the whole domain blocked.

• Wikipedia:Spam-blacklisting
• Wikipedia:WikiProject Spam
• m:Spam blacklist/About
• Special:Log/spamblacklist
• MediaWiki:Bad image list
• Wikipedia:Deprecated sources
• Wikipedia:Wikipedia is not censored
• Wikipedia:Link rot/URL change requests
• Help:Citation Style 1 |url-status= parameter