SOLID

Single responsibility

Open-closed

Liskov substitution

Interface segregation and

Dependency inversion

are the five basic Object-oriented Programming and Design principles.        ~ Uncle Bob

HL7

Health Level-7 or HL7 refers to a set of international standards to transfer clinical and administrative data between software applications used by various healthcare providers. These standards focus on the application layer, which is "layer 7" per OSI model.

~ Wiki