-The ODS-2 filesystem is case-insensitive and does not preserve case.
-Perl simulates this by converting all filenames to lowercase internally.
-
-For ODS-5, filenames may have almost any character in them and can include
-Unicode characters. Characters that could be misinterpreted by the DCL
-shell or file parsing utilities need to be prefixed with the C<^>
-character, or replaced with hexadecimal characters prefixed with the
-C<^> character. Such prefixing is only needed with the pathnames are
-in VMS format in applications. Programs that can accept the Unix format
-of pathnames do not need the escape characters. The maximum length for
-filenames is 255 characters. The ODS-5 file system can handle both
-a case preserved and a case sensitive mode.
-
-ODS-5 is only available on the OpenVMS for 64 bit platforms.
-
-Support for the extended file specifications is being done as optional
-settings to preserve backward compatibility with Perl scripts that
-assume the previous VMS limitations.
-
-In general routines on VMS that get a Unix format file specification
-should return it in a Unix format, and when they get a VMS format
-specification they should return a VMS format unless they are documented
-to do a conversion.
-
-For routines that generate return a file specification, VMS allows setting
-if the C library which Perl is built on if it will be returned in VMS
-format or in Unix format.
-
-With the ODS-2 file system, there is not much difference in syntax of
-filenames without paths for VMS or Unix. With the extended character
-set available with ODS-5 there can be a significant difference.
-
-Because of this, existing Perl scripts written for VMS were sometimes
-treating VMS and Unix filenames interchangeably. Without the extended
-character set enabled, this behavior will mostly be maintained for
-backwards compatibility.
-
-When extended characters are enabled with ODS-5, the handling of
-Unix formatted file specifications is to that of a Unix system.
-
-VMS file specifications without extensions have a trailing dot. An
-equivalent Unix file specification should not show the trailing dot.
-
-The result of all of this, is that for VMS, for portable scripts, you
-can not depend on Perl to present the filenames in lowercase, to be
-case sensitive, and that the filenames could be returned in either
-Unix or VMS format.
-
-And if a routine returns a file specification, unless it is intended to
-convert it, it should return it in the same format as it found it.
-
-C<readdir> by default has traditionally returned lowercased filenames.
-When the ODS-5 support is enabled, it will return the exact case of the
-filename on the disk.
-
-Files without extensions have a trailing period on them, so doing a
-C<readdir> in the default mode with a file named F<A.;5> will
-return F<a.> when VMS is (though that file could be opened with
-C<open(FH, 'A')>).
-
-With support for extended file specifications and if C<opendir> was
-given a Unix format directory, a file named F<A.;5> will return F<a>
-and optionally in the exact case on the disk. When C<opendir> is given
-a VMS format directory, then C<readdir> should return F<a.>, and
-again with the optionally the exact case.
-
-RMS had an eight level limit on directory depths from any rooted logical
-(allowing 16 levels overall) prior to VMS 7.2, and even with versions of
-VMS on VAX up through 7.3. Hence C<PERL_ROOT:[LIB.2.3.4.5.6.7.8]> is a
-valid directory specification but C<PERL_ROOT:[LIB.2.3.4.5.6.7.8.9]> is
-not. F<Makefile.PL> authors might have to take this into account, but at
-least they can refer to the former as C</PERL_ROOT/lib/2/3/4/5/6/7/8/>.