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, or honour. An individual may use several different sets of post-nominal letters. 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.
Fellowship or membership of learned societies, academies or professional institutions (for example, RA, FRCP, FRGS, FRSA)
Membership of the Armed Forces (for example, RAF, RN, RMP)
Listing degrees in ascending order
According to both the University of Oxford and the Chicago Manual of Style,university degrees should be listed in ascending order: bachelor's degrees first, followed by master's degrees, then doctorates irrespective of the order in which one obtained them. However, in the UK, this will not apply in the case of undergraduate master's degrees followed by postgraduate bachelor's degrees (e.g. a Scottish MA followed by a BPhil).
Etiquette for deciding which higher educational qualifications may be listed post-nominally
In the US
In the US, common practice is to name only the highest degree in a particular discipline (e.g., if one had earned one's BS, MS, and PhD in Biology – even from different schools – as well as an MBA in Management, then the preferred listing would be John Doe, MBA, PhD).
In the UK
Practice in the UK varies from that in the US partly because it is designed to draw attention to the fact that not everybody who possesses a higher ranking award possesses lower ones as well. For example, it is perfectly possible to obtain a PhD without getting a master's degree first. It is also possible for somebody who has never received a formal university education to be awarded an honorary degree. Therefore it is customary to list all higher educational awards post-nominally although one should not list step qualifications. In other words, lower awards that are wholly incorporated into higher-ranking awards should not be listed (for example, in the case of an MA from Oxford or Cambridge University, "John Smith, MA" rather than "John Smith, BA MA") - to do so would give the impression that one possesses two distinct academic qualifications.
Following the same principle, when the lower qualification is a passport to the higher qualification (e.g. where a bachelor's degree is a requirement for doing a master's degree) or the credit for a lower award (such as a Certificate or Diploma of Higher Education) is not wholly incorporated into a higher award, lower qualifications may be included. For example, credit for a Certificate of Higher Education can be used to exempt the holder from some of the requirements of a bachelor's degree and in such a case it would be wrong to list one's qualification as "Jane Smith, CertHE BSc". However, if one did not apply some of the credit for one's CertHE to obtaining one's bachelor's degree, it would be acceptable to list both qualifications.
Where two different qualifications with the same name have been obtained (for example an Oxford MA and a postgraduate MA from the University of London), this can be indicated by using the abbreviations of the awarding body, e.g. "Jane Smith MA (Oxf & Lond)".
Etiquette for deciding order of fellowship or membership of learned societies, academies or professional institutions
In the UK and Commonwealth countries, if the individual belongs to more than one, these should be listed in the order of the establishment of the organisation.
Examples of post-nominal letters:
A King or Queen of the United Kingdom is entitled to use the post-nominal R.