Oracle 11g Directory Object Case Sensitive on Linux

I ran into an interesting feature of Oracle 11g on Linux in debugging some PL/SQL code which uses BFILENAME and DBMS_LOB calls to load and process XML files.

There is some case sensitivity to the name of DIRECTORY object, but probably not what you think. The DIRECTORY object must be referenced in the PL/SQL code in upper case regardless of the case you use in creating it.