Say for example we want to store a patient's preference for therapist gender, or a custom "dedupeId" of type DedupeId[] [{type: "AETNA", value: "123456"}]. This is simple to do in postgres / prisma, etc, but sometimes a custom field we want to create is something that needs to be in a hipaa db. We want to use our postgres db for things that dont need hipaa compliance, for fliexibility, but sometimes we have a custom field that we do need hipaa compliance for and so would like to do so in medplum.

Hi @oscadev , For something like an AETNA id, i would suggest using an identifier. Check [this](https://www.medplum.com/blog/demystifying-fhir-systems#identifiers) out for more info. You can also use [FHIR extensions](https://www.medplum.com/blog/fhir-extensions-intro) to add additional information to any resource