The X10 system allows for both zones (letters) and groups (numbers).

At my place all the external lights are the same number - one button turns them all on. They communicate with each other. Cross one IR zone and the whole exterior lights up - all four sides. They also sound a chime module.

Most of my lights are in one zone (letter P), the ones in my master bedroom are in another (letter B). Above my bed is a neon light lit switch mini-panel that with one button will light all the "P" zone - interior and exterior lights but not my bedroom. On the night stand is another panel that allows me to light the bedroom for convience.

The idea is when I hear a bump in the night I want the house lit up but not my bedroom. I feel safer with the lights out in my own room. I keep my handgun in the same location in a lock box that I can open by touch. I have a five "D" cell mag light that provides all the light needed - and a nice less than lethal weapon.

My alarm system doesn't receive inputs from the IR yard lights - just that audible chime. However the alarm system does communicate with the yard lights when it lights zone "P".

I've been using the X10 system for 20 years now - love it.