Associates will be listed on the main site (they count as team members). I'm not sure whether they should be listed in the member directory unless they are also members: leave them out for now.

I think that we were using the term "affiliates" for organisations with whom we have an MOU, such as MySociety or Web Foundation. Again we'd expect them to be listed somewhere, but I wouldn't imagine they would go in the member directory.

Keep it simple for now, just include the four types of member.