> However, I am correct that the way you implemented them on Reddit was to alllow a post to exist in more than one subreddit at once? Not exactly. Today you can post the same link in multiple reddits, since uniqueness is by reddit. You used to be able to crosspost, but we got rid of that after we expanded beyond just a few communities. With tags the implementation was that you could tag any link with any tag, so if anyone submitted the same link elsewhere and used the same tag, that link would show up in the /t/foo list once with a combined discussion thread. The alternative implementation had the link show up twice, each with their own tag. Either way, we didn't want someone to browse to /t/jesus and find links to both /r/atheism and /r/christianity.
Ah, I see. Well, then I suppose that's not too different from how they currently work here, except that you can ignore or follow specific tags. Which is funny, because one of my biggest fears with using tags is that they would turn into something akin to subreddits. :) Thanks for the explanation. It has definitely given me some things to think on. It's interesting that you don't run into a similar problem with posts on atheism and christianity popping up in /r/jesus. But then I guess the space is defended by the expectations of those that came there for jesus.Either way, we didn't want someone to browse to /t/jesus and find links to both /r/atheism and /r/christianity.