Templates work perfectly well without this bit of text (as long as the css is OK). Would love to find out what it (was) is for…
Why 'anchor="page_media_0"' in HTML print contexts?
It has to do with the placement of absolutely positioned elements on a multipage section. You have your standard offsets of Top and Left to determine where on the page, but that anchor determines which page it actually appears on.
Ah. Got it.