How to behave when meeting with the police

What if you stopped "just so"? How to protect yourself from "Militia extortion"? Do you open the militia door? What to do if your minor child is detained? What are the features of communication migrants with the police? Who and how can I protect from the police arbitrariness? These and many other questions are responsible in their book Yulia Konev, Candidate of Law Sciences, Rector of the Institute of Legal and Economic Security.
So, you were detained. Why are you detained, by chance or deliberately reasonable or unfair? You must remember that the police represent the state and you must behave specifically. But you are a person and a citizen - your rights must be observed, and personal dignity is not subject to insult