Same rules as a Traditional Long bow Pat, Can't be cut to center, 1/8 out I think and not elevated. Anyway back to his question, I usually cut in some kind of shelf Then a leather wedge to hold the arrow on the shelf for hunting, the one thing you have to remember is if yo cut the window be sure not to cut it high enough so it is in the working part of the top limb, if it bends at that point it will lift a splinter at best or at worse blow the to limb, no different than violating the longitude grain in the limb anywhere else. My handle is usually plenty thick so haven't had a problem there but have had it split where the cut window meets the top limb.
Pappy