Links to other forums, which are often sponsored by or have adds for other stores, are not allowed as are links to sites that may be sponsored by stores. Links or discussions of other stores are obviously not allowed. Basically, SWF is a store, and as such have the right to request that their competitors don't get free adverts on their board.
Believe me, even I didn't always agree with this policy. And there are still times it irks me. There is a wink and a nod now and then. A "google such and such" to get to an article. But outright mention or discussion is not allowed.
However, after participating on several boards, I realized that I found SWF to be one of the friendliest boards I found, and believe it or not, one of the least moderated in general. On this one, you can pretty much predict what will be cut out...on others, it often was what a particular moderator didn't like in terms of advice that may be contrary to theirs.
There are several political and religious threads in the Aquarium for example, that wouldn't see light of day on many other big boards.