OCLC Connexion has a way to automatically add collection codes above the call number to make printing labels easier. So for example, a spine label will read:
REF
TD9
F332001
instead of
TD9
F332001
This is accomplished by defining an automatic stamp for each oclc holding library code.
Open OCLC Connexion Client -> Tools -> Options -> Printing -> Label Options -> Define Automatic Stamps