Make sure you have a good reason for the check. It will only be accepted to counter vandalism or disruption to Wikimedia wikis. Valid reasons include needing a block of the underlying IP or IP range, disruptive sockpuppetry, vote-stacking, and similar disruption where the technical evidence from running a check would prevent or reduce further disruption.
Be specific in your reasons. Ambiguous or insufficient reasons will cause delays. Explain the disruption and why you believe the accounts are related, ideally using diff links or other evidence.
Make sure there are no local checkusers or policies.
Reason(s): An anonymous person (via open proxies) keeps revealing the full real name and location of another contibutor bg:w:User:Batman tas. The latter explicitely requested that his real name should not be revealed. As this has happened before in the exact same manner, I'd like a confirmation that the offender is the same. --Петър Петров (talk) 20:08, 8 April 2015 (UTC)
We generally do not associate specific IP addresses with registered accounts. Ruslik (talk) 19:32, 9 April 2015 (UTC)
@Петър Петров: If the IP addresses are problematic then block them. The chances of a user who is abusing editing through them is slim, so about the only chance of a confirmation is through a slip-up. Do you really wish for us to continue? — billinghurstsDrewth 09:01, 12 April 2015 (UTC)
The IP addresses were blocked immediately back then. There were no recent incidents with that user. I will request help again if need arises. Consider this request withdrawn. Thanks. --Петър Петров (talk) 20:51, 18 April 2015 (UTC)
Closed as Not done. -- M\A 09:36, 19 April 2015 (UTC)
Reason(s): The above mentioned user has made suspicious acts that resemble to those of the blocked users that constantly come and vandalize Pashto Wikipedia. Kindly check if this username is related to any of the others listed above --Khangul (talk) 21:23, 17 April 2015 (UTC)
@Billinghurst: This is obviously related to #Pastho Wikipedia above. In light of your recent findings and discussion ongoing at SN you may wish to decide on this one. -- M\A 09:38, 19 April 2015 (UTC)
Also not sure that I am comfortable with your choice of words. A different point of view is being exhibited, and you classify it as vandalism. More people have points of view and it is these people at fault. — billinghurstsDrewth 10:24, 19 April 2015 (UTC)
One thing which is clear is that DanKoehl is once again making procedural errors. He has requested CU after stating that TWO more admins were required for support, but only ONE more has currently given support! See this diffStho002 (talk) 00:25, 20 April 2015 (UTC)
@Stho002: Please, count again. Both Faendalimas and MPF obviously support a CU request. Both are admins. One and one is two. Regards --Franz Xaver (talk) 08:04, 20 April 2015 (UTC)
@Franz Xaver: What kind of idiot are you? Koehl said 'Yes we can, if another two admins support your request' [my bold]. He then made the CU request after just MPF added his support. Now let me see, 0 plus 1 equals 1, not 2 (at least according to my maths) ... Stho002 (talk) 20:55, 20 April 2015 (UTC)
Furthermore, DanKoehl is in breach of CU policy, whereby [quote]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[unquote]. Although this is not precisely defined, it is clear what is going on here in the broader context. For one thing, DanKoehl is currently attempting to rewrite local CU policy to suit his agenda better, while conveniently ignoring it for the purposes of the CU request above. Secondly, he has just nominated MPF for WS crat! MPF is permanently banned from enWP, and long ago set himself up as one of my fiercest opponents, even publicly accusing me of copyright violation in a nasty and defamatory/libelous attack on the WS VP. Such a person is clearly unsuitable to be a crat, but DanKoehl is simply promoting all my enemies, with reckless disregard for the good of the project ... Stho002 (talk) 01:14, 20 April 2015 (UTC)
Looking into this, I see that MPF isn't blocked, but only because he jumped before he was pushed. Clearly, he was not confident that an RfC would clear him of any wrongdoing, so he left, never to return. So, I was technically incorrect to say that he was blocked, but it amounts to the same thing ... Stho002 (talk) 04:45, 20 April 2015 (UTC)
PS: DanKoehl misquotes me by using the term 'banned'. I said 'blocked'. DanKoehl probably doesn't know the difference ... Stho002 (talk) 04:47, 20 April 2015 (UTC)
It looks like a duck to me you don't need CU to deal with problematic editors. — billinghurstsDrewth 12:01, 20 April 2015 (UTC)