If you put a link to another user in your signature and then sign, it will ping them. I can't think of a reason why this would be desirable, unless of course you're trying to annoy and harass someone.
From some limited testing it seems that it needs a link to the actual user's page in addition to the other user in order to notify that the other user.
@Amorymeltzer In what proper circumstance can I add [[User:Amorymeltzer| Amorymeltzer]] ([[User talk: Amorymeltzer|talk]]) in my custom signature and then sign discussions with it? I think this is crystal-clear disruption or NOTHERE as they say it and would result in immediate blocking.
I did some additional testing and I could not find a case when links to user pages in a user signature will trigger trigger mention notification, the signature in a form below will be displayed as a link to Another user page, but a mention notification will not be sent:
[[User:Another user| Another user]] ([[User talk: Another user|talk]])
@Etonkovidova Did you see this from my original post?
From some limited testing it seems that it needs a link to the actual user's page in addition to the other user in order to notify that the other user.
If the account's actual username is in there as well, I presume it treats the whole thing like typical wikitext. That is, the requirement for a mention ping (link to user name + ~~~~) doesn't distinguish between text added outside the signature and text added as a result of ~~~~.
Can you provide the actual wikitext that you used for the signature that triggered a mention notification?
Sure thing!
[[User:Amorymeltzer]] [[User:Amory]] is in the signature box for User:Amory, and "treat as wikitext" is checked. Then, simply signing pings User:Amorymeltzer: https://test.wikipedia.org/w/index.php?title=User_talk:Amory&diff=386849&oldid=386705
It also does so even if there is no other wikitext added (both edits in this diff pinged User:Amorymeltzer): https://test.wikipedia.org/w/index.php?title=Talk:Page4242&diff=386851&oldid=386850
Thank you, @Amorymeltzer - with the signature format that you provided the issue has been confirmed; moved the task to Incoming tasks on our team workboard.