I already found this existing question
Is this possible in XHTML: tags in a title-attribute?
…but it seems to be about browser-rendered title attribute.
I’m using a jQuery plugin to render the title attribute, called Tooltip by Flowplayer.
I can already tell you that the rendering of HTML tags contained in title attributes with this plugin WORKS. It shows nicely in FF3, IE7, IE8 and recent versions of Safari, Chrome and Opera.
My question is: is it “legit”?
I only found that the value of title attribute should be “text”. Does it mean plain text or “string”?
Considering that most browsers display the HTML correctly with the jQuery plugin applied, would you think it’s fair to put those tags, EVEN if they’re not “officially” authorized ??
My answer would be to check out directly with a validator (http://validator.w3.org/). If the page is not on the web, open it in your browser and take the source code generated by jQuery and paste it in the validator’s Direct Input tab.
If you want to know what is legit and what isn’t, W3.org is the reference.