To support Extended File Specifications, the Record Management
    Services (RMS) have been enhanced to provide the following
    functions through existing interfaces:

    o  Support for a wider range of characters in a file name,
       extension, and directory

    o  Access to file specifications with extended characters

    o  Support for directory structures deeper than eight levels

    o  Access to file specifications longer than 255 bytes through
       the NAM block with some restrictions in functionality

    o  Access and complete specification of file specifications
       longer than 255 bytes by callers who are aware of the new
       naming characteristics through a new interface (NAML block)

1 - Extended File Names

    With ODS-5 enabled, RMS can manipulate filenames and subdirectory
    specifications of up to 255 8-bit or 16-bit characters in length.
    RMS can handle a total path name 512 8-bit or 16-bit characters
    in length.

    Prior to OpenVMS Alpha Version 7.2, the NAM block interface could
    pass file specifications of up to 255 bytes each (including the
    resultant file specification). The following topics describe the
    changes that allow for passing longer file specifications and
    that provide compatibility with applications using the NAM block
    interface prior to this release.

2 - Additional Character Sets

    With ODS-5, RMS supports access to files and directories whose
    names contain arbitrary 8-bit characters, except for the C0
    control set (hex 00 through 1F) and the following characters:

       Double quotation marks (")
       Asterisk (*)
       Backslash (\)
       Colon (:)
       Left and right angle brackets (< >)
       Slash (/)
       Question mark (?)
       Vertical bar (|)

    Note that this explicitly includes both the C1 character set (hex
    80-9F) as well as graphical and other characters between 9F and
    FF. This allows the entire ISO Latin-1 character set (with the
    7-bit character exclusions noted above) and any defined Unicode
    character.

3 - Deeply Nested Directories

    Under Extended File Specifications on Alpha, RMS supports deep
    nesting of up to 255 directories, with the restriction that the
    total directory specification must be no longer than 512 8-bit
    or 16-bit characters. The deep nesting of directories is also
    supported on ODS-2 disks.