VMS Help Ext File Specs  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Extended File Specifications is a feature of OpenVMS Alpha
    Version 7.2 and later that allows the use of Windows-style
    file specifications.

    Extended File Specifications consists of two major components:

    o  An optional volume structure, ODS-5, which provides
       support for file names that are longer and have a greater
       range of legal characters than in previous versions of OpenVMS

    o  Support for deep directories

    Full Extended File Specifications functionality is available only
    on OpenVMS Version 7.2 (and later) on Alpha. For a description of
    Extended File Specifications functionality, see the OpenVMS Guide
    to Extended File Specifications. The following topic lists the
    Extended File Specifications functionality available on a VAX
    system.

1 - VAX and ODS-5

    Current ODS-2 volume and file management functions remain the
    same on both VAX and Alpha Version 7.2 (and later) systems;
    however, extended file naming and parsing are not available on
    VAX systems.

    Limited Capabilities on VAX Systems
    In mixed-architecture OpenVMS Version 7.2 and later clusters,
    OpenVMS Version 7.2 and later VAX systems are limited to the
    following Extended File Specifications functionality:

    o  Ability to mount an ODS-5 volume

    o  Ability to write and manage ODS-2-compliant files on an ODS-5
       volume

    o  See pseudonames (\pISO_LATIN\.??? or \pUNICODE\.???) when
       accessing ODS-5 file specifications

    BACKUP Limitations
    From a VAX system, users cannot successfully create or restore
    an ODS-5 image saveset. However, these users can successfully
    restore ODS-2-compliant file names from an ODS-5 saveset.