This is a rewrite of my previous post.
The above source is translated into
<h4><a name="itu-r_bt.601" id="itu-r_bt.601">ITU-R BT.601</a></h4>
<h4><a name="auto" id="auto">Auto</a></h4>
I think auto and period are reserved in CSS syntax.
I can't select these IDs in userstyle.css.
Another feature request, if you rename auto to something I would like to ask you to rename it to page_name_auto. (And if there are more than 1 "auto" in a page, page_name_auto1.)
Because our wiki will have too many "Auto", I can't select "Auto" after all.