Duke's Daughter—'The Right Hon. Lady' [Christian name and surname], or 'The Lady' [Christian name and surname], the surname being that of her husband if married. Begin: 'Madam.' Refer to as 'Your Ladyship.' If married to a peer, she is addressed according to her husband's rank only. This, however, does not hold in the case of peers by courtesy; and a Duke's daughter married to the eldest son of an Earl, after the prefix 'Lady,' sometimes takes her own Christian name, followed by her husband's courtesy title.
Duke's Eldest Son and his Children—The courtesy title is treated as if it were an actual peerage; his eldest son taking the grandfather's third title, and being addressed as if a peer.
Duke's Eldest Son's Wife—As if her husband's courtesy title were an actual peerage.
Duke's Younger Son—'The Right Hon. Lord' [Christian name and surname], or 'The Lord' [Christian name and surname]. Begin: 'My Lord.' Refer to as 'Your Lordship.'
Duke's Younger Son's Wife—'The Right Hon. Lady,' or 'The Lady' [husband's Christian name and surname]. Begin: 'Madam.' Refer to as 'Your Ladyship.'
Earl—'The Right Hon. the Earl of ——,' or 'The Earl of ——.' Begin: 'My Lord.' Refer to as 'Your Lordship.'
Earl's Daughter—As Duke's daughter.
Earl's Eldest Son, and Earl's Eldest Son's Wife—As if the courtesy title were an actual peerage.
Earl's Younger Son and his Wife—As Baron's son and his wife.
Governor of Colony—'His Excellency [ordinary designation], Governor of ——.' Begin according to rank, and refer to as 'Your Excellency.'