Rootjazz

Is the username:*word* enough to filter word in any location of username?
or to use this word as filter i have to use all three?
username:*word*
username:*word
username:word*

username:*word*

this will match:

username:*oo*
will match look

username:*oo
will match: loo
won't match: look

usernae:oo*
matches: ooh
doesn't match: look / loo