Well, you don't really go out looking for features, you just muddle through. I created a community filter by hand before I found out by chance that you could do this automatically too. I didn't have the navbar enabled, and I could hardly intuit that attaching letters to the URL would do something, and only finally found out when some person whose LJ I was browsing had put the links in their sidebar, so I saw the URL version with the "c" for comms attached. Even after that I always forgot what you had to do to see feeds.

And it's not like the reading filter page says something like "If you want to create a reading filter beyond the standard f-list display options (people, comms, feeds) you can do that here" either, or anything to cross-reference the other thing, iirc. While I wouldn't want some annoying paperclip always second-guessing what I intend to do, some references to obscure related features wouldn't go amiss within the text, IMO.