Consuetudo pro lege servatur - "Custom is held as law". Where no laws apply to a given situation, the customs of the place and time will have the force of law.⏎
Consensus facit legem - Stipulates that when two or more persons arrive at a good faith agreement, the law will insist on that agreement being carried out.⏎
Delegatus non potest delegare - That which has been delegated cannot delegate further.⏎
De minimis non curat lex - "The law does not concern itself with the smallest things". There must be a minimal level of substance or impact in order to bring a legal action.⏎