Test Wiki:CheckUser/ja
CheckUser is a restricted special page that is fully available only to stewards and system administrators. CheckUser allows authorized users to check and view what IP addresses have been used by user accounts – data which is normally hidden. They can also view some other technical information about browsers and user clients.
A log of CheckUser actions is kept privately. Due to the sensitivity of the tool, Checkuser rights will not be granted to any non-stewards or sysadmins except under exceptional circumstances. Administrators, however, can test the tool on their own account and IP address only.