There were a number of NB comments for C++20 related to UB in the
preprocessor:
https://wiki.edg.com/bin/view/Wg21belfast/SG12
The response was to reject them, but create issues. Did the issues never
get created?

e.g. https://github.com/cplusplus/nbballot/issues/26 doesn't seem to have a
corresponding CWG issue. Is there some other issues list I should be
looking at, or did these get dropped on the floor?