The following list gives the form in which important guests should be included in a preamble in order of precedence:
Your Royal Highness
My Lord Mayor (My Lord Provost, etc) See (i)
Mr Recorder (outside London)
Mr Chairman of the ...... County Council (outside Greater London)
My Lord Chancellor
Prime Minister (or, more formally, Mr. Prime Minister). See (ii)
Your Excellency (ies) (this refers to Ambassadors and High Commissioners)
Your Grace(s). See (iii)
My Lord(s). See (iv)
Ladies and Gentlemen. See (v)
(i) This applies only to the civic head of the city, borough, etc, in which the function takes place. A civic head from elsewhere is mentioned after 'My Lord(s)'. More than one lord mayor or lord provost may be covered by 'My Lord Mayors', 'My Lord Provosts' or by naming each. There is no plural for 'Mr Mayor'; 'Your Worships' is used.
(ii) Also: My Lord President (that is, of the Privy Council), My Lord Privy Seal, Mr Chancellor (of the Exchequer or of the Duchy of Lancaster), Minister(s) (this covers a secretary of state; other ministers are not mentioned in a preamble when the Prime Minister attends a function).
(iii) This covers dukes and duchesses. If the Archbishop of Canterbury is present, 'Your Grace' (or 'Your Graces' if a duke or duchess is also attending) should be mentioned before 'My Lord Chancellor'. Similarly, the Archbishop of York is covered by including 'Your Grace' immediately after 'My Lord Chancellor'. Both archbishops rank before ambassadors and high commissioners.
(iv) For peers other than dukes, peers by courtesy, for diocesan bishops by right and for other bishops by courtesy. In the absence of any peers, the form 'My Lord Bishops' may be used.
(v) When only one woman is present the form should be 'Lady (or 'My Lady' if titled) and Gentlemen', or 'Mrs/Lady Blank, Gentlemen'; never 'Madam and Gentlemen'. The phrase 'Distinguished Guests' is also an acceptable alternative in this circumstance.
Roman Catholic Dignitaries
A cardinal archbishop may be included in the form 'Your Eminence', placed by courtesy after 'Your Grace(s)'. Other archbishops and bishops are by courtesy mentioned in the same way as those of the Anglican Communion.
Clergy, other than archbishops and bishops, should not be included. In particular, the forms 'Reverend Sir' and 'Reverend Father' are archaic. Exceptionally 'Mr Dean', 'Madam Dean', 'Mr Provost', 'Archdeacon' or 'Madam Archdeacon' may be included.
guest of honour
When the guest of honour is not covered by one of the above terms, he or she is included in the preamble by office immediately before 'Ladies and Gentlemen'. This specific mention also applies when an individual who is present has provided the building in which the function is taking place.
Aldermen and sheriffs
Within the City of London it is customary to refer to these as 'Mr Alderman' or 'Aldermen' and 'Mr Sheriff' or 'Sheriffs' immediately before 'Ladies and Gentlemen'. Elsewhere 'Councillors' may be included at civic functions immediately before 'Ladies and Gentlemen'.