Some differences:
French fs uses 9 recips, english sites use 9, 12, 15, or sometimes even 20
in fr long strophes linked to the sponsor are allowed, even when the sponsor name is not mentionated (its more like a blind link), in the english spoken market you cant do that.
In fr you dont need the USC complilance link but the ICRA "etiquette" (an image linked to ICRA site). and thats only in the index page. In the eng. market you need a link to the "18 US.C. ' 2257 compliance notice" in every pages.
french market usually uses a big 18+ image and an "X" to warn people, english sites only uses the warning thing.
Emm...thats all I can think about right now, hope it was useful!
