How do you address an envelope to a couple when the wife has kept maiden name?

Modern etiquette has been quite adaptive to relatively new changes in how individuals retain their identity after marriage. In some instances the choice to retain a maiden name may be professional. The spouse may have a medical practice, or professional reputation where it's beneficial for them to continue using their pre-married name, but still wish to celebrate the fact of their marriage.

In a scenario where a man and woman have married and the woman chooses to retain her maiden name, as well as adopt her married name, the form would be:

Millicent Millhouse-McGillicutty

To address a letter to husband and wife collectively, respecting the spouse's choice to retain her family name, the address would be:

Mr Harold Millhouse

Ms Millicent McGillicutty - Millhouse

(There is no specific order implied in placing one name over the other, other than the neatness of the envelope).

In the US, the form of address would include a 'full-stop' or 'period' after the abbreviated title, such as:

Prof. Herbert Hoffmeister

Dr. Anastasia Meistersinger - Hoffmeister