Zone management in Security Panel

[gbuico]

I have really no idea on where this subject should go.
For other reasons I'm trying to understand more details about the logic of the Security Panel and while checking the file index.html I see clearly a piece of code managing up to 3 zones separately or all of them together.
Plus, somewhere else i see another piece of code managing the situation where you try to arm a zone but some doors are open. The message "ZONE OPEN" is then issued.
I checked all the possible documents but, either I'm dumb or I couldn't find anything about this.
Can anybody give me any idea?
Thanks

Giacomo