CORRECT CEREMONIOUS FORMS OF ADDRESS.
The following are the correct ceremonious modes of addressing and beginning letters to persons of title or holding offices:
Ambassador, British—Address: 'His Excellency [in other respects according to his rank], H.B.M.'s Ambassador and Plenipotentiary.' Begin: 'Sir,' 'My Lord,' &c., according to rank. Refer personally to as 'Your Excellency.' An Ambassador's wife, when resident abroad, is sometimes, but not very correctly, designated 'Your Excellency.'
Archbishop—'His Grace the Lord Archbishop of ——.' Begin: 'My Lord Archbishop.' Refer to as 'Your Grace.' In formal documents the Archbishop of Canterbury is addressed as 'The Most Reverend Father in God, Frederick, by Divine Providence Lord Archbishop of Canterbury, Primate of all England and Metropolitan;' the Archbishop of York as 'The Most Reverend Father in God, William, by Divine permission Lord Archbishop of York, Primate of England and Metropolitan.' But an Irish Archbishop appointed since 1868 is only 'The Most Reverend the Archbishop of ——,' unless he happen to be a temporal peer, in which case he is 'The Right Hon. and Most Rev.'
Archdeacon—'The Venerable the Archdeacon of ——.' Begin: 'Venerable Sir.'
Baron—'The Right Hon. Lord ——,' or 'The Lord ——.' Begin: 'My Lord.' Refer to as 'Your Lordship.'
Baron's Daughter—If unmarried, 'The Hon.' [Christian name and surname]; if married, 'The Hon. Mrs' [husband's surname]. Begin: 'Madam.' If married to a Baronet or Knight, 'The Hon. Lady' [husband's surname]. Begin: 'My Lady.' If the wife of a peer, or of the son of a Duke or Marquess, address as such.
Baron's Son—'The Hon.' [Christian name and surname]. Begin: 'Sir.' But the eldest sons of Barons in the Peerage of Scotland are usually addressed as 'The Hon. the Master of' [peerage title].
Baron's Son's Wife—'The Hon. Mrs' [husband's surname], or, if necessary for distinction, the husband's Christian name should also be used. Begin: 'Madam.' If the daughter of an Earl, Marquess, or Duke, address as such.