Post-nominal letters
Post-nominal letters, also called post-nominal initials, post-nominal titles or designatory letters are letters placed after the name of a person to indicate that the individual holds a position, educational degree, accreditation, office, military decoration, or honour, or is a member of a religious institute or fraternity. An individual may use several different sets of post-nominal letters, but in some regions it may be customary to limit the number of sets to one or just a few. The order in which these are listed after a name is based on the order of precedence and category of the order. Post-nominal letters are one of the main types of name suffix. They should not be confused with pre-nominal letters, which precede the name rather than follow it.
Usage
Order in which qualifications/awards and honours are listed
The order in which post-nominal letters are listed after a person's name is dictated by standard practice which may vary by region.
In the US
In the United States, standard protocol is: