Voici l'approche CSS pure pour la numérotation des titres.

Le code CSS qui suit numérote tous les titres du wiki, ainsi que ceux de la table des matières.

Placez-le dans l'un des CSS du répertoire user de votre thème (ainsi qu'à nouveau dans le print.css pour avoir la numérotation lors de l'impression)

/lib/tpl/THEME/user/screen.css

/* Automatically numbering Headings via CSS 
https://philarcher.org/diary/2013/headingnumbers/ */
 
body {counter-reset: h2}
h2 {counter-reset: h3}
h3 {counter-reset: h4}
h4 {counter-reset: h5}
h5 {counter-reset: h6}
 
h2:before {counter-increment: h2; content: counter(h2) ". "}
h3:before {counter-increment: h3; content: counter(h2) "." counter(h3) ". "}
h4:before {counter-increment: h4; content: counter(h2) "." counter(h3) "." counter(h4) ". "}
h5:before {counter-increment: h5; content: counter(h2) "." counter(h3) "." counter(h4) "." counter(h5) ". "}
h6:before {counter-increment: h6; content: counter(h2) "." counter(h3) "." counter(h4) "." counter(h5) "." counter(h6) ". "}
 
h2.nocount:before, h3.nocount:before, h4.nocount:before, h5.nocount:before, h6.nocount:before, #dw__toc h3:before, #panel h5:before { content: ""; counter-increment: none }
 
/* Automatically numbering Table of Contents (TOC) via CSS
https://www.freecodecamp.org/news/numbering-with-css-counters/ */
.dokuwiki #dw__toc ul ul {
  list-style-type: none;
  counter-reset: css-counters 0; /* intializes counter, set -1 for zero-based counters */
}
 
.dokuwiki #dw__toc ul ul li div.li:before {
  counter-increment: css-counters;
  content: counters(css-counters, ".") " "; /* generates inherited counters from parents */
}
 
/* Styles des titres */
div#content .dokuwiki h1,
div#content .dokuwiki h2 {
  font-weight: bold;
}
 
div#content .dokuwiki h3,
div#content .dokuwiki h4,
div#content .dokuwiki h5,
div#content .dokuwiki h6 {
  font-weight: normal;
}
 
div#content .dokuwiki h1 {
  font-size: 160%;
}
 
div#content .dokuwiki h2 {
  font-size: 140%;
}
 
div#content .dokuwiki h3 {
  font-size: 132%;
}
 
div#content .dokuwiki h4 {
  font-size: 116%;
}
 
div#content .dokuwiki h5 {
  font-size: 100%;
}
 
div#content .dokuwiki h6 {
  font-size: 80%;
}

Placez le fichier suivant dans l'un des CSS de votre thème (template) (ainsi que dans le print.css pour avoir la numérotation lors de l'impression) ou dans un userstyle.css dans votre répertoire ./conf :

Pour le thème monobook :

/doc/lib/tpl/monobook/user/screen.css

/*
   Place for user defined CSS rules (screen media) - this file can safely be
   preserved when updating. See README for details.

   Note: All example files are delivered with the ".dist" extensions to make
         sure your changes do not get overwritten when updating the template.
         Just remove the ".dist" extension to use them.
*/

/* headlines */
div#content .dokuwiki h1,
div#content .dokuwiki h2 {
  font-weight: bold;
}
div#content .dokuwiki h3,
div#content .dokuwiki h4,
div#content .dokuwiki h5,
div#content .dokuwiki h6 {
  font-weight: normal;
}

div#content .dokuwiki {counter-reset: level1;}
.dokuwiki #dw__toc:before,
.dokuwiki #dw__toc:after {counter-reset: level1; content: "";}
.dokuwiki #dw__toc h3:before{content: ""}
 
div#content .dokuwiki h1, .toc-body ul.toc li.level1 {counter-reset: level2;}
div#content .dokuwiki h2, .toc-body ul.toc li.level2 {counter-reset: level3;}
div#content .dokuwiki h3, .toc-body ul.toc li.level3 {counter-reset: level4;}
div#content .dokuwiki h4, .toc-body ul.toc li.level4 {counter-reset: level5;}
div#content .dokuwiki h5, .toc-body ul.toc li.level5 {}
 
div#content .dokuwiki h1:before,
.dokuwiki ul.toc li.level1 a:before {
    content: counter(level1) ". ";
    counter-increment: level1;
}
div#content .dokuwiki h1.sectionedit1:before,
.dokuwiki ul.toc li.level1 a:before {
    content: none;
}
div#content .dokuwiki h2:before,
.dokuwiki ul.toc li.level2 a:before {
    content: counter(level2) ". ";
    counter-increment: level2;
}
div#content .dokuwiki h3:before,
.dokuwiki ul.toc li.level3 a:before {
    content: counter(level2) "." counter(level3) ". ";
    counter-increment: level3;
}
div#content .dokuwiki h4:before,
.dokuwiki ul.toc li.level4 a:before {
    content: counter(level2) "." counter(level3) "." counter(level4) ". ";
    counter-increment: level4;
}
div#content .dokuwiki h5:before,
.dokuwiki ul.toc li.level5 a:before {
    content: counter(level2) "." counter(level3) "." counter(level4) "." counter(level5) ". ";
    counter-increment: level5;
}

Ce CSS fonctionne avec monobook :

screen.css

div.dokuwiki {counter-reset: level1;}
div.dokuwiki #dw__toc:before,
div.dokuwiki #dw__toc:after {counter-reset: level1; content: "";}
div.dokuwiki #dw__toc h3:before{content: ""}
 
div.dokuwiki h1, .toc-body ul.toc li.level1 {counter-reset: level2;}
div.dokuwiki h2, .toc-body ul.toc li.level2 {counter-reset: level3;}
div.dokuwiki h3, .toc-body ul.toc li.level3 {counter-reset: level4;}
div.dokuwiki h4, .toc-body ul.toc li.level4 {counter-reset: level5;}
div.dokuwiki h5, .toc-body ul.toc li.level5 {}
 
div.dokuwiki h1:before,
div.dokuwiki ul.toc li.level1 a:before {
    content: counter(level1) ". ";
    counter-increment: level1;
}
div.dokuwiki h1.sectionedit1:before,
div.dokuwiki ul.toc li.level1 a:before {
    content: none;
}
div.dokuwiki h2:before,
div.dokuwiki ul.toc li.level2 a:before {
    content: counter(level1) "." counter(level2) ". ";
    counter-increment: level2;
}
div.dokuwiki h3:before,
div.dokuwiki ul.toc li.level3 a:before {
    content: counter(level1) "." counter(level2) "." counter(level3) ". ";
    counter-increment: level3;
}
div.dokuwiki h4:before,
div.dokuwiki ul.toc li.level4 a:before {
    content: counter(level1) "." counter(level2) "." counter(level3) "." counter(level4) ". ";
    counter-increment: level4;
}
div.dokuwiki h5:before,
div.dokuwiki ul.toc li.level5 a:before {
    content: counter(level1) "." counter(level2) "." counter(level3) "." counter(level4) "." counter(level5) ". ";
    counter-increment: level5;
}

• (en) https://www.dokuwiki.org/start?id=tips:numbered_headings

Basé sur « Numbered headings per CSS only » par Geabulek.