How to skip numbering for some first topics?

[MyMoon]

Hi team!
How to organize chapter numbering like this:

Preface.................1
Abbreviations list.....3
1. System purpose....5
..............

?

Sincerely,
Dmitry

[Dan]

You may find useful the documentation:

https://www.oxygenxml.com/doc/versions/ ... intro.html

The built-in CSS rules are in: [PLUGIN_DIR]/css/print/p-numbering-shallow.css and [PLUGIN_DIR]/css/print/p-numbering-deep.css . The first CSS contains the rules that add a "Chapter NN" before the first level topics from the publication, the later contains rules that add a deep structure of counters on all topics referred from the map, at any level.

The PLUGIN_DIR is the {oxygen installation directory}/frameworks/dita/DITA-OT3.x/plugins/com.oxygenxml.pdf.css

You may alter and copy the rules to fit your needs.

Many regards,
Dan