During every school I attended growing up (and I graduated in 2007 so this isn't that ancient history) my parents would just call the school office if something

During every school I attended growing up (and I graduated in 2007 so this isn't that ancient history) my parents would just call the school office if something urgent came up, and the faculty would use the intercom system to page the room I was in. The teacher paused their lesson, acknowledged the request, and asked me to pack my things and head up to the front office, no questions asked. It was infrequent, but very well understood and executed efficiently. I'm not sure smartphones have improved on this? If a kid gets a call in class the teacher's almost immediate reaction is annoyance, because there was no chain of authority that led to that distracting element. Now the kid's on the defensive and has to explain that it's their parent, and the whole class gets to wait while the kid awkwardly has this conversation while simultaneously communicating with the teacher that it's a legitimate request, etc. And that's for legitimate emergencies, to say nothing of the troublemakers that will intentionally coordinate fake calls to get out of class and hang out with their friends.