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Dokumentationen skrev:
Step 5, The default: You can specify a "default" or "d" parameter to the URL, this should be urlencoded so as to make it to our servers intact. There are "special" values that you may pass to this parameter which produce dynamic default images. These are "identicon" "monsterid" and "wavatar". If omitted we will serve up our default image, the blue G. A new parameter, 404, has been added to allow the return of an HTTP 404 error instead of any image or redirect if an image cannot be found for the specified email address.
http://www.gravatar.com/avatar/3b3be63a4c2a439b013787725dfce802?d=identicon
http://www.gravatar.com/avatar/3b3be63a4c2a439b013787725dfce802?d=monsterid
http://www.gravatar.com/avatar/3b3be63a4c2a439b013787725dfce802?d=wavatar
http://www.gravatar.com/avatar/3b3be63a4c2a439b013787725dfce802?d=404
