Besides the following, are there any HTML tag attributes that have a URL as their value?
href
attribute on tags:
,
Check out the W3C's list of HTML attributes, there's a "type" column in there and just look for URI types.
And of course the HTML 5 version of that list is useful too (edit: updated link for HTML 5.2 here)
So for HTML4 we've got:
HTML 5 adds a few (and HTML5 seems to not use some of the ones above as well):
and
These aren't necessarily simple URLs:
![]()
or
or
SVGs can also contain links to resources:
In addition, the style
attribute can contain css declarations with one or several urls. For example: