Quote Originally Posted by RoyalVariations View Post
for example, a het for caramel "TSK" line bred with a het for Caramel "VPI-Nerd". If a Caramel is produced = "TSK + VPI-Nerd", two lines combined Caramel.

A two lines combined Caramel "TSK + VPI-Nerd" bred with a "BHB" het, if any Caramels are produced = "TSK + VPI-Nerd + BHB", three lines combined.

they must be compatible!
That makes some sense, but I don't think it proves you combined the three lines. Genes come in pairs, so your TSK + VPI-Nerd + BHB is probably only TSK + BHB or VPI-Nerd + BHB. To truely prove they are all compatible you would need to breed just a TSK to a BHB and a VPI-Nerd to a BHB.