FLuid breaks on HTML data-* attributes
Trying to use HTML5 data-* attributes in Fluid ViewHelpers breaks rendering in different ways, depending on the ViewHelper called.
For example f:link.action doesn't parse the tag completly, rendering breaks with "You closed a templating tag which you never opened!"
Adding a data-* attribute to f:form.textbox results in the unparsed tag being put into the resulting html.
Regarding the use of data-* tags see the official W3 documentation:
Bug experienced on Extbase/Fluid included with TYPO3 4.4.0beta1