Wow, that is a good list. There are a few items where it's not up-to-date, but it's the best list I've seen! Just wish it had version numbers (or dates) listed, too.
If you don't have the car or track when you try to join, you'll get the last car/track you were using and then be bounced. If you're only missing the car, then nice admins let you join the track so you have a chance to chat to find out what you're missing <ahem, that's a hint for admins>.
Some helpful abbreviations:
VLM = Virtua LeMans
MMG = Mac Modders Group
TPSCC = The Pits Stock Car Challenge
TPTCC = The Pits Touring Car Challenge
NAGT = North American GT (made by the Pits)
ORR = Off Road Racing
RaceX = conversion of Race 2007 & newer Simbin property
HGTTC = Historic GT & Touring Cars (aka Historix), conversion of GT Legends
Overall, though, if you're trying to find something, check on rFactor Central and then, if it's not found, Google the term or ask around.