Board Thread:Support Requests - Getting Technical/@comment-33841760-20180101224143/@comment-31600514-20180101231341

They only check IP's of a vandal or a spammer. They don't do checkuser requests. For that you need to use Special:Contact/general.

Edit: If you meant how normal users do, before they report it: Vandals often doing the same things. For example they create accounts with names that are meant to insult an local admin for example. On small things like this you cann recognize them.