(Updated) Sometimes what's not in Wikipedia is even more interesting than what it contains. Deletionpedia is a site that catalogs everything that gets deleted from Wikipedia, from temporary deletions during clean-up to complete entries that are removed after a period of discussion. Some have been on Wikipedia for years and have hundreds of edits, while others are vanity entries or obscure points of reference that have been barely touched. Deletionpedia has collected nearly 64,000 deleted pages from Wikipedia.

Have some time to kill? Go back and reread the list of minor bounty hunter characters in the Star Wars universe, deleted for lack of source material, and deemed by one editor as "fanfic material." Geek lore seems to be a particular target for deletion, with the deleted page of the month a comprehensive guide to "Weapons of the Imperium (Warhammer 40,000)". Deletionpedia provides links back to the Wikipedia deletion discussions, which are a lesson in magnification of minutiae; the Warhammer page was removed due to philosophical disagreements over what can be considered credible source material, while a page listing every chalkboard gag in The Simpsons' opening credits spent 691 days on the site before being deleted as "fancruft."

Deletionpedia would make a fine research project for sociology students to study what groupthink does when applied to a community-built compendium of knowledge. Better yet, a thorough review of the discussion pages may lead to a new psychological disorder being named, based on the need to examine trivial knowledge to a level of minutiae never seen before.

Update/Follow-up:

• A Catch 22 for Wikipedia: Should Deletionpedia entry be deleted?
• Effort to delete Deletionpedia entry on Wikipedia fails
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