The letter was written by the Danish shipowner A.P. Møller to his son, Mærsk Mc-Kinney Møller, on 2 December 1946, at a time when the son was taking on greater responsibility within the family firm.

In it, Møller sets out advice on the conduct of business and character, expressing the principle that has since become closely associated with the Maersk group: that no loss should befall the company which could be avoided through what he termed “rettidig omhu” – commonly rendered in English as “constant care” or timely diligence.

The phrase has become a defining motto of A.P. Moller-Maersk and is frequently cited in Danish business culture. The letter is remembered less as a formal document than as a statement of the values – foresight, prudence and attentiveness – the founder sought to pass to the next generation.