Funny explanation of SysLog severity levels

emergency(...any)

aliases: emerg, panic.

Use cases: Your application is completely broken. If you sleep, you must wake up and begin to repair your application.

alert(...any)

Use cases: Your application does not work. If you going to go to bed, you should not do it, you must begin to repair your application.

critical(...any)

alias: crit

Use cases: Your application is running, but can be broken soon. If you eat, you should do it quickly and begin to repair your application.

error(...any)

alias: err

Use cases: Your application is running, but something bad happened. You must add the task "fix the bug" to your to-do list.

warning(...any)

alias: warn

Use cases: Your application is running, but soon you may see error messages. You should add the task "fix the bug" to your to-do list.

notice(...any)

Use cases: Your application is running, but something unusual happened. You have to think about it in your spare time.

informational(...any)

alias: info

Use cases: Your application works fine. These messages show how well.

debug(...any)

Use cases: You can use it during development. And do not use in production environment.

This explanation is taken from mag logger facade.

Mag logger facade provides a simplified interface to various logging mechanism. See on github:
https://github.com/mahnunchik/mag-logger-facade