TSRef - TypoScript Reference
4.1.15. loginUser
Syntax:
[loginUser = fe_users-uid, fe_users-uid, ...]
Comparison:
Matches on the uid of a logged in fe_user. Works like 'usergroup' above including the * wildcard to select ANY user.
Example:
This matches any login (use this instead of "[usergroup = *]" to match when a user is logged in!):
[loginUser = *]