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): Request to prolong this user's autoblock if possible. Recently its socks are very active on several articles, such as this one (notice accounts with username start with "Albert"). A list of discovered socks is available here. Please notify me if such requests can't be submitted through this page. Techyan（Talk） 00:57, 12 February 2019 (UTC)
Autoblocks aren't configurable through wiki interface; it is configuration settings. — regards, Revi 07:14, 12 February 2019 (UTC)
Let me try to explain it in a clearer manner. This user is socking prolifically, the list of socks are found here. Based on local Checkuser policy , a CU can be conducted to find out the underlying IP / ranges of IP of all the accounts and then do a CU block (which must then be oversighted) to prevent new socks accounts to be created from the IP / ranges. This is what we are requesting. Anymore details do co-ordinate with Techyan. I am here to just explain on behalf what exactly is needed in more details. Best Regards, --Cohaf (talk) 18:39, 12 February 2019 (UTC)
On hold pending some related internal discussions. — regards, Revi 03:15, 13 February 2019 (UTC)
@-revi and Cohaf: Ctrl+F on this page and look for keyword "Albert". All recently discovered socks edited this page. Please block their IPs if what they are using are concentrate enough, or more ideally, all of them are using the same IP, and immediately oversight block logs - that's what we have always been done on zhwiki. --Techyan（Talk） 03:42, 15 February 2019 (UTC)
It is allowed to block the underlying IP or range of IPs to prevent abuse, as specified in the Access to nonpublic personal data policy s.4(b)(v) - "the public, when it is a necessary and incidental consequence of blocking a sockpuppet or other abusive account". It is more complicated in this case because it is against our policies to take actions that a sysop could take (local blocks) when there are local admins who could perform them. This request is still on hold for the time being, as it is still under discussion. – Ajraddatz (talk) 00:23, 16 February 2019 (UTC)
Question: It seems that "extend the auto block" means "check the IP and enforce the CU block (if possible)". I have checked the log and I've found out that some stewards had done something similar before (though some of the logs have been removed). --云间守望 13:59, 18 February 2019 (UTC)
Reason(s): Suspected sockpuppet. They are editing the same range of accounts and have an astonishing similarity of username between 1 and 3 (seems to be the same name), while 1 and 2 gets similar user page at user page history and edits the same field. 1233 | Questions?| This message is left by him at 01:29, 21 February 2019 (UTC)