 After the suspect is charged, the murder is considered closed/solved even if the suspect is not convicted; this is why, earlier in the season, Rawls pushes for arrests on murders in order to help the statistics, even though the cases are weak.Bunk uses this phrase when Omar discusses his rules for life on the street.It also refers to the codes that the law and the street also follow, such as that there should be no talking on phones about business which Stinkum breaks resulting in being berated by Stringer.