What do the call numbers for books in the locked stacks mean?

Call numbers provide inventory control for libraries, as well as locational information for shelving and retrieval. Please ask for help interpreting catalog records for locked stack material at the Medical Historical Library between 1:00 p.m. – 4:30 p.m weekdays, or ask at the Circulation Desk anytime.  After hours, send an email inquiry to historical.library@yale.edu.