Hi all, As I had a lot of questions regarding these rights so let me go back on this point. The only concern I have is to avoid anonymous contribution. As Google doesn’t provide a way to give right to "anyone signed in” I had to put the doc in read only by default. I also wanted to have someone in charge for each workshop (i.e someone writing a proposal). I gave edit rights to these persons. These persons in charge are free to give edit rights to other (i.e. they organise their work as they want). Some of them will prefer give comment right to avoid text erasing, it’s up to them. When you need to get right to a doc, the best way is too connect and request it from google so the persons receiving the request will have your google id. Antoine