Descriptive and brief headings are crucial to the quality of the documentation. Sphinx uses the headings within the ReST files to generate the navigation of the HTML output and the outlines of the PDF files. The Clear Linux* OS publishes the documentation as HTML making consistent heading levels extremely important.

In addition to the title of the file, only three levels of headings are accepted. The following example shows all accepted levels of headings:

Title
#####

Level 1 sections
****************

Level 2 sections
================

Level 3 sections
----------------

Headings must be written in sentence case. Learn more about the correct capitalization in our grammar guide.