Punishability does not requires a written act ofparliament and cannot be based on custom.

The legality principle ‘Nulle Poena Sine Lege, Nullum Crimen Sine Lege,’ which states that an act may only bepunished if criminal liability had been established by law before the act was committed.

Criminal prohibitions must determine the prohibited conduct, they must be definite (the principle of certainty)

Acts cannot be punished retroactively. (the principle of non retroactivity)

The statutory prohibition cannot be extended by analogy to conduct not covered by the ordinary meaning of the words used. (the principle of the interdiction of analogy)