this controls the behavior of global destruction of objects and other
references.
+=item PERL_ROOT (specific to the VMS port)
+
+A translation concealed rooted logical name that contains perl and the
+logical device for the @INC path on VMS only. Other logical names that
+affect perl on VMS include PERLSHR, PERL_ENV_TABLES, and
+SYS$TIMEZONE_DIFFERENTIAL but are optional and discussed further in
+L<perlvms> and in F<README.vms> in the Perl source distribution.
+
+=item SYS$LOGIN (specific to the VMS port)
+
+Used if chdir has no argument and HOME and LOGDIR are not set.
+
=back
Perl also has environment variables that control how Perl handles data