lucy24 - 7:50 pm on Nov 20, 2012 (gmt 0)
Works fine but for obvious reasons keeps redirecting. So far I've tested [ ], [R], [R=301,L] and [L]. All result in multiple redirects. Up to (5 times, Total elapsed time: 0 seconds)
Empty flag? Really? I've never tried that: would expect a 500-class error.
A redirect goes into an infinite loop because each request is an island, and redirecting doesn't change the referer. (Neither does reloading the page.) So the [L] flag will only affect the rest of mod_rewrite. Since you've given the complete protocol and domain, it is de facto an [R] of some kind, regardless of other flags.
Rewrite and redirect are different things-- as is [F] of course-- so you have to decide what you want your result to be and make a rule for that.
Once you've figured out whether you want a redirect or a rewrite you can figure out how to exclude requests that have already been handled.
Does (tld|tld) in the initial Rule mean that you want to exclude two different tld's like-- picking an example wholly at random-- .ru and .su? You can use any tld in posts, so long as the meat of the name is example dot something.