In speaking, simply address them by name- either first or last, depending on your relationship to them. The Jr. or III is mainly used in writing.
John Doe, III is an example.
You would address the letter to John Smith III. This is the proper way to denote that he is the third person in his family line with the name John Smith.
what is the proper way to address the mayor
The proper way to address the conductor of a symphony orchestra is 'Maestro.'
The proper way to address an envelope for a Ph.D. is "Dr. [Full Name]" followed by their address.
the proper way to address the Queen is by "your majesty" or Ma'm, pronounced like "ham'
"Your honor"
usted. or ustedes.
Gentlemen
The proper way to address a Doctor of Osteopathic Medicine (DO) (not Doctor of Osteopathy) is Doctor (Dr.) since they are medical physicians.
Master John Doe
What is the proper way to address a meeting location in the Board Room of a building