Lars Aronsson wrote:
Neil Harris wrote:
A possible point in favour: using rel="alternate" together with the hreflang attribute in <link> elements (as per http://www.w3.org/TR/REC-html40/struct/links.html#h-12.3, section 12.3.3) might help search engines make smarter decisions about indexing Wikipedia content, thus increasing the relevance and availability of Wikipedia content in Web searches made by the general public.
That's an interesting statement. What evidence do you have to support it? Can you name any search engines that actually look at this information?
I think it's a chicken-and-egg problem, a case of "if you build it, they will come."
Although I do not know of any search engine that uses this information, on the other hand, it's hard to prove a negative. Google, in particular, are highly ingenious in using every scrap of information they can glean from analyzing web pages, and feeding it to their machine-learning pattern-matching engines. Certainly, unless that information is present, they will certainly not be able to use it, even in theory.
I think that encoding the metadata statement "this other page is an alternative to this page, in the following language" in a standardized machine-readable form is quite likely to be useful, possibly in unanticipated ways.
Indeed, the application of this link tag to Wikipedia is a clear case where both of the normal objections voiced to the hreflang attribute (no control of linked-to content, what about Accept-Lang) clearly do not apply.
It's simple to implement, clearly cannot do any harm to Wikipedia's content, and it might do some good; whether it is worth the additional load on Wikipedia's bandwidth and servers is another matter.
-- Neil