I'm working on some thank-you correspondence following an event, and have run into a new situation I don't know how to deal with correctly. One of the guests is an Army officer, but he also has a Ph.D. Do I use one and not the other, or do I combine them like "Col. Dr." or something? Please advise.
Robert Hickey, author of Honor & Respect: The Official Guide to Names, Titles, & Forms of Address, makes it pretty clear: only military titles and honorifics are used. They aren't combined with academic or other honorifics, like "Professor," or post-nominal abbreviations like "Ph.D." To Etiquetteer's surprise, this also includes religious honorifics.