NAME

       Perl::Critic::Policy::Documentation::ProhibitDuplicateHeadings - don't duplicate =head
       names

DESCRIPTION

       This policy is part of the "Perl::Critic::Pulp" add-on.  It asks you not to duplicate
       heading names in "=head" POD commands.

           =head1 SOMETHING

           =head1 SOMETHING      # bad, duplicate

       Duplication is usually a mistake, perhaps too much cut-and-paste, or a leftover from a
       template, or perhaps text in two places which ought to be together.  On that basis this
       policy is medium severity and under the "bugs" theme (see "POLICY THEMES" in
       Perl::Critic).

   Default Uniqueness
       The policy default is to demand that a given heading is unique to its ancestors, siblings,
       and to the immediately adjacent heading irrespective of level.  This is designed to be how
       human readers perceive the scope of headings and subheadings, plus adjacency in case a
       mixture of heading levels would let a duplicate otherwise go undetected.  For example

           =head1 Top

           =head2 Subhead

           =head3 Top              # bad, duplicates its ancestor head1

       Or siblings

           =head1 Top

           =head2 Down

           =head2 Another

           =head2 Down             # bad, duplicates sibling head2

       Or adjacent

           =head2 Blah

           =head1 Blah             # bad, duplicates adjacent

       A subheading can be repeated if it's under a different higher heading.  For example the
       following two "Details" are cousins, so allowed.

           =head1 One

           =head2 Details

           =head1 Two

           =head2 Details          # ok

   All Unique
       Option "uniqueness=all" (see "CONFIGURATION" below) applies a stricter rule so that all
       "=head" names must be unique throughout the document, irrespective of levels and
       structure.

           =head3 Foo

           =head1 Bar

           =head3 Foo             # bad

       One use for this is to ensure all headings can be reached by an "L<>" link.  An "L<>" only
       has the heading name, no level or path, so if there's any duplication among the names then
       only the first of each duplicate will be reachable.  (The POD browsers usually go to the
       first among duplicates.)

       This rule is often too strict.  It can be good to have similar subheadings like "Details"
       as shown above, with no need to make such sub-parts reachable by a link.

   Disabling
       If you don't care at all about this you can disable "ProhibitDuplicateHeadings" from your
       .perlcriticrc in the usual way (see "CONFIGURATION" in Perl::Critic),

           [-Documentation::ProhibitDuplicateHeadings]

CONFIGURATION

       "uniqueness" (string, default "default")
           The uniqueness to be enforced on each heading.  The value is a comma-separated list of

               default     currently "ancestor,sibling,adjacent"
               ancestor    don't duplicate parent, grandparent, etc
               sibling     same level and parent
               adjacent    immediately preceding, irrespective of level
               all         all headings

           The default is "default" and the intention is to have default mean a sensible set of
           restrictions, though precisely what it might be could change.

           For example in your .perlcriticrc file

               [Documentation::ProhibitDuplicateHeadings]
               uniqueness=ancestor,adjacent

SEE ALSO

       Perl::Critic::Pulp, Perl::Critic

       Perl::Critic::Policy::Documentation::ProhibitDuplicateSeeAlso,
       Perl::Critic::Policy::Documentation::RequirePodSections

HOME PAGE

       http://user42.tuxfamily.org/perl-critic-pulp/index.html

COPYRIGHT

       Copyright 2013, 2014, 2015, 2016, 2017, 2019, 2021 Kevin Ryde

       Perl-Critic-Pulp is free software; you can redistribute it and/or modify it under the
       terms of the GNU General Public License as published by the Free Software Foundation;
       either version 3, or (at your option) any later version.

       Perl-Critic-Pulp is distributed in the hope that it will be useful, but WITHOUT ANY
       WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
       PURPOSE.  See the GNU General Public License for more details.

       You should have received a copy of the GNU General Public License along with Perl-Critic-
       Pulp.  If not, see <http://www.gnu.org/licenses/>.

perl v5.32.1                  Perl::Critic::Policy::Documentation::ProhibitDuplicateHeadings(3pm)