QUOTE (qpsnapper @ Sep 19 2008, 16:37)

I don't think that someone registered with another club could play as a trialist either in his own association or from a different league set up, if he is already registered with a club then that would surely have to be a loan arrangement?
If I'm right with that, then only an unregistered player could play as a trialist. From memory, if a player is a trialist, you annotate the team line with "TR" beside his name and then on the reverse you mark his full name, date of birth, address and their last registered club. If he was already registered elsewhere then the loan arrangement would be required.
I'm guessing therefore that you probably could play a guy from the terracing if your left back doesn't turn up (although that could only be in league games as you can't play trialists in cup matches).
In short: a trialist is an unregistered player who is turning out on a temporary basis for a team.
QUOTE (cmontheloknow @ Sep 22 2008, 19:22)

A player currently registered with a Junior club can play as a trialist for a Senior club. It's relatively common. The Junior club has to grant permission though. The same loosely applies to Amateur players but there is no formal registration for the players of amateur clubs in amateur competitions (I believe). It's less common for Seniors to play Amateur trialists (because of the quality gap) but the smaller clubs in the Juniors do it all the time for league matches. Again, permission is needed from the Amateur club.
I believe both of those posts are correct entirely as regards official senior league matches.
We have already named a junior trialist (with permission) on our bench this season at one point, though he wasn't used.
There doesn't appear to be any restriction on playing trialists registered for other clubs in "official" friendlies though. Cammy Bell turned out for us in several pre-season friendlies with permission from Kilmarnock before we actually signed him on loan.
EDITED to add: You could certainly play a guy off the terracing if you needed to in an emergency in a league match provided he wasn't registered to anyone else. We named our first team coach Stevie Morrison as a Trialist sub keeper on a couple of occasions last season which is effectively the same thing.