Checkusers may need to block an editor on the basis of technical checkuser evidence, due to disruption caused by abuse of multiple accounts or IP addresses. These blocks are marked as a {{Checkuserblock}} in the block summary and must not be reversed by non-checkusers without consulting a checkuser.

As checkuser data cannot be shared publicly and a checkuser block may involve other pertinent non-public information, an unblock appeal for a {{Checkuserblock}} must only be reviewed by a checkuser. A reversal of a check user block by an administrator without consulting a checkuser may result in the removal of permissions.

In exceptional cases, there may be a need to block an editor on the basis of oversighted information that cannot be shared publicly. In such a case, the available oversighters may jointly act on the basis of group consensus. If there are insufficient oversighters available or if additional input is required they may consult the Wikimedia stewards.

Except in an emergency, non-oversight administrators should not block on the basis of information known to them that has since been oversighted. An administrator believing that such a block is required should contact one of the oversighters privately or email oversight-commonslists.wikimedia.org.

Any block made under this section should be reported by the oversighters to the community at the earliest opportunity, with as much background material as can reasonably be provided.

An editor who is blocked under this section may not be unblocked without the approval of the oversighters. An editor who wishes to have their oversight block reviewed should approach the oversighters privately, who will consider the request as a group. Public ‘appeals’ on the talk page of the blocked editor should not be used, and any that are posted may be removed.

Blocked users are informed that they may request unblocking. They may do this by adding {{unblock|reason for the request}} to their own user talk page. Alternatively, they may request unblocking with an appropriate reason via e-mail to the blocking administrator or another administrator.

An appropriate reason will almost always include one of the following:

• An acknowledgement that the block was appropriate and a credible promise that the behaviour that led to the block will not be repeated
• An explanation of why the block is not appropriate based on this and other relevant policies and guidelines or is likely to be a mistake or an unintended side effect

An unblock request may be granted or declined. Before granting a request to lift a block placed by another administrator, the reviewing administrator should consult with the blocking administrator, except in obvious, uncontroversial cases. Requests made on user talk pages may only be declined by an uninvolved administrator. Unblock requests for blocks marked with {{checkuserblock}} will be reviewed by a checkuser.

Making repeated unblocking requests without appropriate reasons may be considered abusive. As noted above, users who have abused or are likely to abuse the ability to edit their own user talk page and/or send e-mail in this or any other way may have either or both of these privileges revoked, which also prevents these privileges from being used for unblocking requests.

• Category:Block warning templates
• Category:User block templates
• User:Blocking subject, a test account for blocking practice
• m:Global locks, m:Global blocks, and m:Global bans: similar concepts spanning all Wikimedia projects