In my last post, I noted that 'Les Revenants' on DVD in French comes without any subtitles. It seems that subtitles are a more complex topic than they first appear.
For example, if you watch 'Engrenages' on French DVD with subtitles, towards the end of the titles there appears (in the subtitles) the information that the subtitles are by 'Lezard'. It looks like subtitles are in this case farmed out to another company, separate to other parts of production/publication.
A couple of weeks back I was enquiring whether netflix offers French subtitles if you watch French programs on an British netflix account. The answer is 'no', and the reason is interesting - the subtitles for 'Engrenages' are not licenced for use outside France. There's that 'different companies' thing in action.
Before I had occasion to use non-English subtitles, I just assumed that DVDs came with all the subtitles/languages that the program is available in. It seems not, there's a lot of variation from country to country. If you want to watch something with subtitles in a language other than that of your country of residence, you're probably going to have to get the disc imported (especially since netflix now forbid VPN connections).
One other thing - we watched 'Adele Blanc Sec' at the weekend. If you buy a British edition of a French film, with English subtitles, you can't switch them off. Subtitles on foreign language films are not switchable using the DVD subtitle facility, they're built into the picture.