How to Remove the 'chapter NN' Prefix from Table of Contents and Content.Edit online
If you are using the shallow numbering CSS (this is the default), and you want to hide the "Chapter" prefix, use the following rules in your customization CSS:
For the TOC:
*[class ~= "map/topicmeta"] > *[class ~= "topic/navtitle"]:before { display:none !important; }
For the titles in the content, change the content of the title :before
(this example just uses the chapter number):
*[class ~= "topic/topic"][is-chapter]:not([is-part]) > *[class ~= "topic/title"]:before { content: counter(chapter) ". "; }