Last modified: 2009-04-10 20:02:46 UTC
In the query http://en.wikipedia.org/w/api.php?action=query&list=logevents&letype=renameuser&lestart=20090402000000 , three log entries have been nuked using RevisionDelete. The output for these entries is below: <item logid="21530545" pageid="0" actionhidden="" type="renameuser" action="renameuser" userhidden="" timestamp="2009-04-01T21:08:41Z" commenthidden="" /> <item logid="21530519" pageid="0" actionhidden="" type="renameuser" action="renameuser" userhidden="" timestamp="2009-04-01T21:08:27Z" commenthidden="" /> <item logid="21530489" pageid="0" actionhidden="" type="renameuser" action="renameuser" userhidden="" timestamp="2009-04-01T21:07:19Z" commenthidden="" /> All three entries have both actionhidden="" and action="renameuser", so the action is not hidden at all.
log_type/log_action are irrelevant and not meant to be hidden. Hiding the action means hiding the action text, which often includes bad titles and possibly parameters.