I agree with Kroc about @cite. I've found it utterly useless in so many situations. I suppose it's good for quoting anything you can somehow put into a uri. (Does it accept any URI or just URLs??)
e.g. If you're citing a book you could do: <q cite="urn:isbn:whatever-number-here">. That's the good thing about ISO numbers, they qualify as URNs. So, I guess that does cover a lot of works. But as Kroc said, it still doesn't apply to things like emails, etc. But now that I think about it more, how could it?
I suppose @cite could represent a URI and a new @citedesc attribute could be added.
e.g. <blockquote citedesc="An email from Joe">.
This could be useful to the reader by doing:
blockquote::after { content: attr(citedesc); font-style: italic; }
As for the cite element.
<cite> can technically be used in closing in a <blockquote> if it is referencing a work, however, it shouldn't be used to quote a person.
(The html5 spec makes it a point of saying, "A person's name is not the title of a work — even if people call that person a piece of work").
Using <cite> for website names is an interesting question. To me, I don't intuitively see websites as "works", but if you are using a website as a source in some kind of essay or piece of literature, do you not cite it? I guess it depends on the content. Would you *ever* use Twitter as a source for anything? Probably not.
But then again, when you do cite a website in an essay/treatise/whatever, you're not just citing the site, you're citing the web page itself. You're citing an individual *document* on a web site.
Kroc is *very* right about not always obeying the spec. (To mention dictionaries again in this post...) Dictionaries describe and define words based on peoples' general usage and consensus definition of them, *not* the other way around -- Why has the html5 spec allowed trailing slashes on self-closing elements even when it does nothing in most html parsers right now (aside from Opera)? What did they add semantics to <i>, <b>, and <hr> based on? What did they change the semantics of <header> and <aside> for? It was all based on the authors' general usage of those elements.