[quote=@miette]
Then I'd say if they are so integral to anyones post - they should consider a) playing the character themselves/ finding a player to take on the commitment - b) if it is only a passing reference, should it be in the post at all.
[/quote]

Passing references are a hallmark of a shared universe. Go to any of the Lee/Kirby stuff, and you'll see a ton of it.