Reading the logs... How to?

Hello to you all!

I was wondering if there is any reference available on what is expected to be found when scrolling through log files -mostly jicofo and jvb- to try and diagnose the cause of issues with my setup. It has happened more than once that -while screen sharing- the moderator lost connection to the room, with the gray screen and the countdown to reconnect.

Any hints on where and what to look specifically?

I tried filtering by warnings or by severe but I have no reference on how each incident is classified within the log.