It's not really a requirement, it's just not something I ever considered. I think the main problem would be the announcement of the partners. How will the partner know who to address their reply to if they don't know their name, for example? And if one person is allowed to be signed up as 'anonymous', other characters might want that and we'd eventually get 'anonymous 1', 'anonymous 2', etc.

If you've got any plans on how to make it work, though, I'd love to hear about it!