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