BRIOSCHI Elfrida Consultant said:
I knew that you cannot block an admin because he can
simply unblock
himself. There were some experiments on it.wiki (have a look to
http://it.wikipedia.org/wiki/Speciale:Log/block), but I cannot
understand if there's a problem or is the right behaviour.
This is the expected behavior of the MediaWiki software.
Whether it's allowed is a matter for policy. For instance the English
Wikipedia currently has blocks for users who revert an article more than
three times in twenty-four hours. The policy on that particular Wikipedia
explicitly states that an admin should not unblock himself if blocked for
this reason.
Also blocking only affects editing. A blocked admin on Mediawiki can
still use his admin powers (for instance rollbacks, to perform the
equivalent of reverts.)