The Guidelines were in the Welcome section, posted there by a previous administrator several years ago and recently updated in July of last year.
They have now been removed from there and posted as a announcement.
The Guidelines now form a Terms of Use and form part of the process of registering on this site, requiring you to agree to these terms before you can register, and abide by these rules if you wish to continue using the site.
These terms are also viewable when you login manually into the site using the Login link at the top left of the default board style.