Dear all, I revived the return_type_tinfo-system again. Functions and symbols can take a tinfo_t argument. The idea is that user-defined return_type_tinfos are made by doing something like tinfo_static_t my_rtt_static; tinfo_t my_rtt = &my_rtt_static; After that, my_rtt can be used to label kinds of noncummativity. I implemented the representation labels of clifford and color objects by making an array of tinfo_static_t objects of size 256. My only concern is that archiving/unarchiving may not go completely right, but I do not know that as I did not yet try it. At least some code of myself that used this system works again and does so with minimal changes. Best, Chris