Nested sections
reach at some level
(depending on the document class and output format)
a level
that is not supported by the output format.
Unsupported in LaTeX and HTML5 (HTML5 reserves the 1st level for the document title).
Unsupported in HTML4.
Unsupported in ODT.
Note, that the "reference name" for this section is derived from the content before substitution. You can link to it with the phrase reference "substitutions fail". This behaviour may be exploited to get intelligible IDs after identifier normalization of the section's reference name.
If the URL given to images and figures hints to a video format supported by HTML 5 (MIME types 'video/mp4', 'video/webm', or 'video/ogg'), the HTML5 writer will place it in a video element.
A class option value "controls" tells the browser to display controls for video playback.
It is a good idea to include width and height attributes. If height and width are not set, the page might flicker while the video loads. According to the HTML5 spec, hight and width must be specified as pixel values.
Simple test video in a centered figure
A video like this can be included inline via substitution.