Case_Preservation

   Mixed-case and lowercase file names are retained in their
   original form on ODS-5 volumes. However, the file system on
   OpenVMS preserves the case of file names as they are first
   entered. When you create more than one file with the same name
   differing only in case, DCL treats the subsequent files as
   versions, and converts them to the same case as the original
   file.

   For example, the following commands:

   $ CREATE CaPri.;1
   $ CREATE CAPRI
   $ CREATE capri

   produce the resulting files:

   CaPri.;1  CaPri.;2  CaPri.;3