There's a police brotherhood among cops both within their respective department and those fellow officers who are employed in other departments.
Every cop knows what is required to do this job- they know the difficulties, stresses, and risks that we all take day in and day out.
Every patrol officer knows how tough it is. Working graveyards, fighting the exhaustion, dealing with drug addicts, gangbangers, seeing dead bodies, and seeing countless other things that just aren't fun.
In other words, officers can relate to other fellow officers.
And at times, they provide one another with a little professional courtesy. It's not something that is exclusive to just police officers.
No matter what the profession, whether a teacher, firefighter, or accountant, people can relate to other people who have a bond through common experiences. And common experiences can develop through occupations.
The difference is, as cops, we have a little more ability to "assist" one another. This one fact seems to irk some members of the pubic. If you're working and speaking to someone for blowing a traffic signal red light, you will on occasion, run into the joker who will heckle you, challenge you, and suggest that you would be giving him a break or caution if he was police officer. Well, he might be right, lol. But, I wouldn't throw it into his face and say to him, "yeah you're right. Too bad for you, you unlucky bastard."
That won't go over well.
Keep one thing in mind. Just because officers can provide a little courtesy to one another doesn't necessarily mean that all officers WILL do that. If you happen to be driving a little too quickly down the street, and you get stopped by an officer and you are able to somehow discreetly point out that you are an officer, HOPEFULLY they'll just give you a caution and send you on your way.
But not all cops are like that.
If it appears that the officer that has you stopped isn't going for the old "wink and the nod" routine, just sit tight. Let them do their job, that's what they're paid for. Getting into an argument roadside isn't going to accomplish anything. It might just make things even worse for you.