A website called uniforminsignia.org has this field guide to Cambodian police ranks and insignia. The keys read from top to bottom and from left to right:
staff sergeant – first sergeant – sergeant-major (kiss me goodnight)
warrant officer – chief warrant officer.
major – lieutenant-colonel – colonel
I’ve been told that the rank of police captain doesn’t carry a lot of clout – “a captain sleeps on his motorbike.” I’m still trying to find out what responsibilities the various higher ranks would carry – what rank, for instance, would the head of police at khan level carry?