Principle of legality in French criminal law
The principle of legality in French criminal law holds that no one may be convicted of a criminal offense unless a previously published legal text sets out in clear and precise wording the constituent elements of the offense and the penalty which applies to it. (Latin:Nullum crimen, nulla pœna sine lege, in other words, "no crime, no penalty, without a law").
Source: Wikipedia — Principle of legality in French criminal law (CC BY-SA 4.0)