Well maybe like 2 words : DON'T IMPERSONATE
You wouldn't even think there were actual rules regarding this given the fact of how many firms try to market themselves as paramilitary or private police.
Badges (don't use the 5 point sheriff's star)
Vehicle Lights (don't use any other color than Amber/Green)
Titles (don't use agent, sheriff, patrolman, trooper etc)
Don't use state seal
Uniforms (ID yourself as security)
It feels much like a series of DON'TS, but there is a section on regulated activity with only one sentence:
"Definition - Providing, or advertising as providing, the service of guarding persons or property for compensation."
Given how all these rules are relative to only one thing, they should of just added "and without pretentiously acting as a law enforcement or gov't agency."
Here's a link to the official handbook