From a reader:
What is the correct form of address for a religious who is a deacon? The internal lore of the community is that one retains "Brother" but some of the younger brothers are insisting on "Deacon." I have a general aversion to calling deacons "Deacon" and bishops "Bishop", mostly because I have an aversion to calling you "Priest Z". [Thanks!] In any case, the National Director for the Permanent Diaconate is the source which people cite on this score, but that says explicitly in the introduction that it doesn’t bind religious. So, do you have any ideas? This is a not-terribly-important question as most religious deacons will only be so for a few months, but it’s a good thing to get straight.
There are different customs for addressing Bishops.
In the USA we say "Your Excellency". In the UK we say "My Lord". An Archbishop, I believe, would in the UK be "Your Grace".
In the USA we say to Deacons "Reverend Mister". I think that is the same in the UK. However, I recall once at a gathering in London I addressed a deacon as "Reverend Mister" and he immediately snapped "Reverend DOCTOR". He had a rather high opinion of his own degree.
I abhor this bare address "Bishop" or "Deacon". It lacks decorum.