couples file format?
 

I've been unable to determine the format for the couples file (*.cpl). I'm generating a hybrid mesh externally and know which hexes join to which tets, but don't know the final pieces of the format to have star-cd (v3.26) stop complaining about bad couples. Writing a couples file from star (using the same verts, cells, and boundaries but using CPCREATE) I think I've deduced part of it:

(couple number) (#a) (#b)

(master) (face of master) (slave1) (face of slave1) etc

repeat with next couple

From the written file #a = 3, #b = 1, and all the face numbers = 1. I'm not sure what the remaining values mean, and why duplicating it in my self-generated file would have star comment on partial boundaries and warnings about faces potentially not matching. The only final guess I have is correctly numbering the faces (even though the written file didn't have any different values); if that is the case, what determines the face number?

Thanks for any help.