Determining which design pattern to best implement this feature

The system comprises of a student portal and an admin portal. The feature is the ability to submit applications for certifications that an admin will review and process.

The certifications are as follows:

Alpha - non expiring initial general cert required by all certs Bravo - cert for special area of knowledge of Alpha Charlie - another cert for special area of knowledge of Alpha Delta - another specialization of the Alpha cert

BravoRenewal - a renewal after Bravo expires CharlieRenewal - a renewal after Charlie expires DeltaRenewal - a renewal after Delta expires

They each have certain requirements that differ from the rest but they are all types of certifications.