Hey Pat!
Do you have a tool?
I build lots of cabinets. Face frames have dado's in the rails and stiles to receive the sides, tops, and bottoms.
Using a Festool Domino I use Domino tenons to attach rails to stiles, butt joint style.
So, my bottom and top rails have dado's that also butt into the sides of the stiles. I use a router freehand to cut a short matching dado in the side of the stiles to match up with the dado in the rails, after gluing the face frame together.
I do this freehand with a router and normally this is not a big deal appearance wise as this cut out is on the back side of the face frame. You basically never see it.
The problem I am having with this technique however is that for the last couple of years I have been also using back face frames. Now that cut out is exposed on the front of the back face frame so it has to be perfect.
So you have a jig that will let me cut a short dado in the side of a stile to match and or mate up with the dado in the rail? Clear as mud?
Thank you for any in site.
PS I do have an idea for a jig that uses the stock that will fit the dado to size arms on the jig to guide an upper bearing flush cut bit.