Data to be shown on van

[allanb]

I'm trying to help a friend who has imported a van from the UK to France, and who has been told that he has to fix a sticky label on it to give the information that would be required on a French vehicle.  He has the label, which is pre-printed, but he doesn't speak French.  I do, but there are two items that defeat me:

(1) One is 'PTRA': I have found that this means poids total roulant autorisé, but what exactly is this?  How does it differ from the PTAC?

(2) Another is the single letter 'S', inviting an answer in square metres.  It seems a reasonable guess that it means surface, but (if so) the surface of what, exactly?

Thanks in advance for any information.

[AnOther]

PTRA (authorized travelling total weight)
The sum of the PTAC of the towing vehicle and that of the trailer.

Assuming it doesn't have a tow bar then this would be the same as PTAC I guess.

"S" I can't help you with I'm afraid.

Edit:

Have a look here

http://www.code-route.com/remorque.htm

[allanb]

PTRA - I should have thought of that.

I did some more googling and finally found the mysterious "S" - it does indeed mean surface, but it's simply defined as the length times the width.  Since both the length and the width are declared on the same plate, it seems a bit superfluous.

My friend's plate is now complete.  Thanks for your help.