Illegal Glove

[mach3]

I guess it has been discussed before, but I can't find it.
Codes of interest are ISF and ASA.

What determines the position of a defensive player, especially considering the use of a special glove / mitt?

Say F3 positions herself in the leftfield and catches the flyball with her mitt. Would that be an illegal catch?
Or more general: Does the position in the infield determine which glove a player is allowed to use or the position marked in the line-up?

And if a player uses an illegal glove, how do I call it? Do I treat it like an appeal play or do I call: "Illegal catch!", but let the play run, since the coach has an option?

Thanks

Raoul