<abbr> <acronym> <longdesc> ...

[Percept]

Does anyone know if these tags have any use for SEO ? I would test this myself but I don't feel like waiting 2 months to know the result.

[incka]

I've got no idea... I was looking at tags like that recently, some don't seem to do anything...

[chromate]

I'm pretty sure, they don't do a thing. At least in the case of google. I could be wrong though. But I've not heard of it before.

[megamanXplosion]

I do not know if they do anything for you in SEO-terms, but I would still use them for the sake that it couldn't hurt you in any way. I'd say that the acronym tag would help you in terms of SEO because it's nothing more than an expanded definition of the text it surrounds, but I cannot make any promises for that claim.

I especially like it when webmasters do use the acronym tag. It saves me a lot of time having to Google around for the expanded definition. Most users will not do research to figure out what an acronym means and will simply leave the page in confusion. Why not just help them out? It's not like it will hurt you to include it. Just put acronyms/abbreviations into acronym/abbr tags and use CSS to give them a slightly-visible dotted underline and a help-cursor, this way people (*ahem* IE users) will know that you have some helpful tips spread throughout your pages.

[Mike]

Everyone would be doing it if it was useful imho.

[megamanXplosion]

Maybe, maybe not. I didn't find any SEO resources saying that it was good, and I didn't find any SEO resources saying that it was bad. Usually when something is bad, it gets a lot of exposure. Considering that the ONLY time I see acronym tags being used is on good content sites and have NEVER seen them on anything else would indicate that the amount of abuse of the tag is very low. I don't think Google would penalize you for using it since it doesn't appear to be abused much, and you'd be penalizing yourself (ie: irritating your users) for not using it ;)

[Chris]

Irrelevant to SEO.

[incka]

I would have agreed with Chris, but I'm unsure after going to some sites...

I think it is proberly coinsidence, but...

[Percept]

Incka you said A , I'm waiting for B :)

[incka]

Well just look at the top sites in certain keywords, alot of them use unusal tags such as the ones mentioned, and use <strong> instead of <b>, etc.

I think it's pure coinsidence, but I might be wrong...