I would like to make a message like "You are about to block yourself! Are you sure you want to do that?" except it targets ONE user on the wiki and it would say for example "You are about to block the founder. Are you sure you want to do that?". Is that possible?
Topic on Project:Support desk
What you could do without too much of a hassle is change the according interface text and add the sentence, which you are missing.
Anyway, I think that is superfluous: If you don't trust administrators or if they cannot use MediaWiki correctly, they should not have administrator privileges.
It is a test wiki. And how could I change the according interface text? I know how to for all users but I'm not sure for a specific user.
Here is an overview of the different interface texts, which are used on that page:
https://www.mediawiki.org/w/api.php?action=query&meta=allmessages&refix=ipb-
In order to change one of them in your wiki, go to the according page in the MediaWiki:... namespace in your wiki. E.g. in order to change the text called "ipb-blockingself", edit the text on the wiki page MediaWiki:ipb-blockingself in your wiki.
Thank you.