I can't find a precise answer on that question :
Are parameters which are sent by PUT passed in the URL, or in the HTTP header ?
I think it's the HTTP header, but when I submit my form with the PUT method, it appends the parameters to the URL !
Are parameters which are sent by PUT passed in the URL, or in the HTTP header ?
Not the headers. It's the same as POST - either the URL or the body of the request. The only difference is the HTTP verb being used and of course the semantics that come with it (UPDATE a resource on the server).