Unable to answer "What number or code identifies this stop?" – S University + State (Bus Stop) – https://osm.org/node/560921099 via StreetComplete 57.4:

MBus #: C201
AATA #: 1287

Attached photo(s):
https://westnordost.de/p/211970.jpg
https://westnordost.de/p/211971.jpg