I don't understand where the confusion would lie. What's not to understand about an out of service sticker?
When a scale cop puts a truck or driver out of service, a prominent sticker is placed on the truck. If the truck or driver is not placed out of service, no OOS sticker is placed on the truck.
That's how it works, right? (I have never been placed out of service so do not know from personal experience.)
In theory, yes, it is. In practice, um.....not so much.
Sometimes, the law enforcement, um, 'professional' will state on an inspection report that a sticker was issued, despite there not being one issued, and direct you to meander to the nearest rest area to rectify the CLEARLY OBVIOUS SAFETY HAZARD that resulted in placement out-of-service, but with only a warning (no citation) on the inspection report.
Kinda nullifies the whole spirit of the whole ou-of-service thing, if ya ask me.
Caps added because I haven't yet located the sarcasm font.