kkidd1,
You mentioned 3/16 to 3/4. If you're looking for a prequalified joint designation for CJP with backgouge, why not use B-L1a-S for up to 5/8 thick, and then use B-L2c-S for the 3/4, or just use B-U4b-S for all thicknesses... if there's not an issue with any of the "notes"?