Sorry. I found this lacking in clarity and not helpful at all. I still don't know what the difference is between the 2 kinds of frames. There was much waving around of objects but the topic of what the difference never got zeroed in on.
The difference is the TOP BAR of the frames.. The wedge style top bar has a little strip of wood that can be removed. That way if you’re using wax wired foundations, you can put the wire under the strip of wood (holding it in place) and then staple it back on. Grooved style does not have the strip.. and is usually only used with plastic wax coated foundations.. The wedge style frames can be used with BOTH kinds of foundations.