I am showing my support for rev=canonical over rel=short* and reasoning here: http://erikvold.com/blog/index.cfm/2009/4/21/revcanonicalgood

rel=”shortcut” is more precise than rel=”short[er]“.

Evidence would seem to suggest that paired, reciprocal rel values (e.g canonical/ shortcut) are less prone to human error than rel/ rev pairs – that’s apparently why “rev” was removed from HTML (not, as suggested, because of lack of use-cases).

The problem of hijacking though falsely-claimed canonicity would be negated if cross-domain rel=”shortcut” (or whatever) + rel=”canonical” were only allowed where they are reciprocal; otherwise ignored. Shorteners should thus use latter, regardless of Google et al ignoring it for search aggregation.

There would seem to be no need to include “alternate” in rel=”shortcut” links, indeed its use may be bogus.

Shorteners which don’t handle “#” fragments are, in my view, broken and to be avoided.

No apologies for watching paint dry; someone has to take care of this stuff, or everything will end up in silos, or broken, or both.

http://singpolyma.net/2009/03/delegating-to-multiple-openids/#comments

is giving back:

http://singpolyma.net/p/431

Which does not go to #comments at all.

Although rev=”canonical” feels right, I suggest insisting that the URL it points to MUST have a rel=”canonical” back to the URL claiming to be the canonical version, otherwise do not trust the resource making the rev=”canonical” claim. Yes, two-way linking – it’s very Xanadu-like, but I feel its absolutely necessary to protect the genuine canonical version of content. And this should fit neatly into the purpose of short-URL linking, the non-canonical version in these cases isn’t expected to be canonical, merely a pointer to the canonical version.

Mike.

If you use link element with rel=alternate and type=text/html then the media attribute (media=shortener) may be your best extrapolation of intent. Media is a comma-separated list, meaning you could declare a value such as “twitter,email,shortener” if desired.

Declaring a link element of rel=alternate with type=text/html and a non-empty href attribute on a text/html document is definitely confusing for the renderer. What is this alternate that appears exactly equal (in type, lang, and charset) to the currently viewed document? Language selection is the most common user-facing interface for such head data.

See link types from the HTML 4 spec for more details: http://www.w3.org/TR/html401/types.html#type-links

I like the rev approach. If people find a legit use for it I bet they’d de-deprecate it in HTML5.

Good idea! I wrote a similar solution up the other day as well:

http://sites.google.com/a/snaplog.com/wiki/short_url

cheers,

r.S.

I’d prefer to see something semantically clear and actually previously spec’d like rev=”canonical” – rather than something less clear like rel=”alternate shorter” just because it happens to be not deprecated by someone somewhere.

Lots of obscure and not-so-well understood parts of HTTP and HTML have been eventually put to good use, so why not @rev now?