Wikipedia:Requests for checkuser/header
CheckUser is the process of checking information about two or more users (including named users and IP addresses). Some administrators are able to check if two or more accounts have been used from the same computer. These users also see User agents. This can help them decide if two accounts are related in the way described above. It is also possible to see if a user is editing from an open proxy.
On this page, users can request some users or IPs to be checked. Good reasons should be given for why a checkuser is needed; you should provide links which show the questionable edits, etc. Questions should usually be created so that they can be answered by yes or no. Responses will be short in order to comply with Wikipedia privacy policy. Sensitive information (like the IP addresses used by an account) are usually not reported. The results are not always clear, and a decision should not be made only on the basis of checkuser results.
Use of the tool
This tool is to be used to fight vandalism, to check for sockpuppet abuse, and to limit disruption of the project. It must be used only to prevent damage to the project.
The tool should not be used for political control; to apply pressure on editors; or as a threat against another editor in a content dispute. There must be a valid reason to check a user. Note that alternative accounts are not forbidden, so long as they are not used in violation of the policies (for example, to vote more than once or to make it look like more people support an idea). Checkusers will refuse a request, if the reason for checking is not good enough to warrant the use of the tool.
Please see the CheckUser policy for all the rules related to CheckUser.
The list of users with CheckUser access can be seen at: Special:ListUsers/checkuser.