Can data-* attribute contain HTML tags?

Question

I.E. What gives?\"/>

Answer 1

I'd say yes, as in it's still valid HTML5. Older browsers (which ones?) may not parse correctly.

Section 3.2.4.1 Attributes of the current HTML5 draft says this:

Except where otherwise specified, attributes on HTML elements may have any string value, including the empty string. Except where explicitly stated, there is no restriction on what text can be specified in such attributes.

HTML tags inside attributes also validates at http://html5.validator.nu