I fill them out anytime I suspect a bone may be broken; when kids have been in a scuffle resulting in injury; playground injuries involving playground equipment... to name a few. I say, when unsure if it is necessary, go ahead and do it. Better to be safe than sorry! Welcome to school nursing!
I make an accident report for any injury involving the face, eyes,nose, mouth... any head injury that is more than a mere "bumped head on desk" type... Injuries of the neck or back...injuries that result in limping, significant bruising or bleeding, or suspected fracture. And i call parents for all of the above. Most of the injuries I see are pretty minor, but I don't want any parent to get their child off the bus and say, "OMG,WHAT HAPPENED?!!"