# text.div
This code system http://hl7.org/fhir/type-derivation-rule defines the following codes:

Code | Display | Definition
specialization | Specialization | This definition defines a new type that adds additional elements and optionally additional rules to the base type.
constraint | Constraint | This definition adds additional rules to an existing concrete type.

# description
How a type relates to its baseDefinition.

# concept[].definition
This definition defines a new type that adds additional elements and optionally additional rules to the base type.

# concept[].definition
This definition adds additional rules to an existing concrete type.