Thanks for the link, but that's completely unrelated. This is not about two-factor, this is about using another authentication provider for the entire login, for example OAUTH.
Hi,
We have a custom account system used for our main site, and we use vBulletin for our forum, which has no facilities for integration with an external authentication provider. Thus, we have a steady stream of confused customers who don't understand that the forum and the site have separate...