Basic things about the game. I would say "Knowing how to keep a mob red" would be "Basic education of the game". Especially if they're so afraid of "Vultures", you think they would research a way to keep mobs red. It just seems like a basic preventative measure.
Well sure, it's easy to say that after someone has had a bad experience. As far as it being basic knowledge of the game I'd say it's not really. It's something that people learn over time through experiences of losing claim and etc. It's knowledge that I'd suggest is usually learnt as a reactionary measure, rather than before the fact like strategies. It's probably pretty far off the radar of players who are entering into Abyss for the first time. It's even further off the radar for people who don't have an interest in browsing forums and the like (yes, they're real players too). Hell I've been playing since 2004, have done a lot of content, and I've learnt things about the claim system in the past few weeks that I didn't know. Do you know why I'm learning new things? They just didn't matter as much as they do now in the current game. The hate mechanics have never before caused the volume of issues they are causing now.