Qualifiers that follow a person’s name, for example, “Sr.”, “Jr.”, “III”, “3rd”, etc.
The <suffix> should be used for parts of people’s names, not for degrees such as PhD or DDS. The academic degrees are part of the information that is known about a contributor, not part of the name of the contributor. Degree and certification information may be placed directly after the person’s name:
<contributor ...> <name> <surname>Smyth-Jones</surname> <given-names>George</given-names> <suffix>Sr.</suffix> </name> <degrees>PhD</degrees> </contributor>
Any combination of:
... <name> <surname>Moellering</surname> <given-names>R. C.</given-names> <suffix>Jr.</suffix> </name> ...