I'm now writing occasionally for Burgundy Wave, the Rapids SB Nation site, and one of the articles I suggested for the start of the season was a quick overview of refereeing for fans. The idea being to help them understand some of the things I've learned about refereeing from reading the ref forums here. I wanted to get any suggestions from refs on what you think I should cover. I'm not looking for tough refereeing situations but more basic things that fans get wrong that would be easy to explain what's right. My list so far: Advantage - If you see a foul and are wondering why it wasn't called, look to see if the ref has his arm in the air. He's saying he saw the foul but believes the team has a better advantage by continuing play, etc. Handling - Why every hand ball isn't a foul Offside - Why its not called right away when its obvious (attacker must make a play on the ball), when it doesn't apply (own half, throw ins, etc.), and how defenders affect it Cards - What the rules are for carding and why a ref can't just pull a card because he feels like it VAR - When VAR can be used
May also want to address the concept of trifling, role of 4th official, and other offside situations like gaining an advantage (rebound plays).
I would say the concept of "in the opinion of the referee" and like threeputz said "trifling contact v. Foul".