What does 'N.B.' stand for in Latin?

Answer 1

The abbreviation 'N.B.' comes from the Latin phrase 'Nota Bene'. The English equivalent of the complete phrase is most commonly rendered as follows: [May you] Note Well. In modern spoken English, the equivalent is more likely 'Pay attention'. For the phrase is intended to call attention to a particular aspect or detail of whatever is under discussion.

Answer 2

The abbreviation n.b. is the modern English version of the Latin phrase nota bene (note well, or take good notice). This is used in modern textbooks to emphasise a particular point.