A puzzle cache that is a real mystery!
The above coordinates are for the Hughes Main Library. The container is located at REF 423. Please replace it precisely.
Finding the cache container is one thing, but unlocking it is quite another!
Decipher the code clue below and voila!

After signing the log, please reset the locking code to 000.
Many thanks to Greenville County Library System for permission to place this cache. The cache can be completed during times that the Library location is open to the public. Visit their website for a listing of their hours of operation by location to complete your mission.
https://www.greenvillelibrary.org/locations