In Elk there is this option coming from the far past of the internet, when search engines were barely able to parse static html pages and didn't know very well how to deal with "strange" urls, the "Search engine friendly URLs".
In the current implementation, the option converts the urls from something like:
http://www.ElkArte.net/community/index.php?board=1.0
to stuff like:
http://www.ElkArte.net/community/index.php/board,1.0.html
Nowadays, if you talk about "Search engine friendly URLs", people will think immediately to something like:
http://www.ElkArte.net/community/feature_discussion/
So, there are a couple of points:
1) the software delivers the wrong message, Elk is not able to have "friendly URLs" in the meaning given nowadays to this sentence, it just gives another version of the same stuff (i.e. board and topic ids in the URL),
2) to search engines there is no difference between the two forms of the URL.
I would propose to drop the option.
Of course, drop it entirely now is not a good thing, mainly because it would mean lots of index content becoming 404 and that would be bad.
So we need at least a couple of phases:
1) phase one, remove the option from the admin panel, that way it will be less easy to enable it, at the same time, the option will be deprecated (I'd say this could even be in 1.1), any website with the option already enabled would still use it,
2) phase two, implement "proper" (in the meaning of today) friendly URLs (still the previous code will work behind the scenes redirecting to the new URLs), this could be in 2.0,
3) drop the code and provide an addon for those that actually like that form of the URL (3.0 or 2.0 if we want to merge phase 2 and 3).
Opinions?
ETA: now that I finished to write, I feel we already had a similar discussion... if you find it I'll merge the two.