=head1 DESCRIPTION
-This is not the perldebug(1) manpage, which tells you how to use
+This is not L<perldebug>, which tells you how to use
the debugger. This manpage describes low-level details concerning
the debugger's internals, which range from difficult to impossible
to understand for anyone who isn't incredibly intimate with Perl's guts.
of an C<o ...> debugger command (q.v. in L<perldebug/Options>).
=head3 Debugger internal variables
+
In addition to the file and subroutine-related variables mentioned above,
the debugger also maintains various magical internal variables.