Contra non valentem agere nulla [or non] currit praescriptio - A statute of limitation does not run against those who cannot act; this is the basis of the American discovery rule limiting prescriptive limitation periods.⏎
Delegatus non potest delegare - That which has been delegated cannot delegate further.⏎
Dubia in meliorem partem interpretari debent - "Doubtful things should be interpreted in the best way". Often spoken as "to give the benefit of the doubt".⏎
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.⏎