I'm in favor of this idea.  A couple of comments:

1. The *all+*default part is very important.  Current functionality is actually broken, because changing its value (changing the type of *all+*default) won't change the constant (Card::DefaultTypeID).  It's another constant that shouldn't be a constant.
2. One rule should be: if it's absence breaks things, it should have a codename.
3. The invite stuff doesn't follow that rule.  I actually don't want codenames for those.  It should be fine for those plus cards not to exist.  Especially since that functionality is going to change soon so that this stuff uses flexmail.  Giving it a codename means migrating stuff in and then migrating it away again soon.  It's not that much code just to do the lookups (and it doesn't happen often enough to be a performance concern).
4. Re no permission, we have "nobody" permission for comments.  We may be able to use something like that.

How does 'nobody' work?

Isn't that sort of a hack in the code now? A more formal mechanism may be better, no?

  --Gerry Gleason.....2012-12-10 17:46:59 +0000

hmm, I guess it's actually just an empty permissions rule. So, in fact, we may already support this, to some extent. The only difference is we don't really have a way to support Wagn Bot - only. always_ok? refers to Wagn Bot + accounts with administrator role. I suppose we could just make an is_bot? method...

  --Ethan McCutchen.....2012-12-10 18:14:04 +0000