The Simple reference set type represents an extensional definition of a subset of components. The components can be concepts, descriptions, relationships and reference sets.  Therefore, the reference set contains a list of references to one or more components.

The components can be specified for inclusion or exclusion for a specified purpose. For example, the contains the concepts that are important for general practice and family practice medicine. In this section we will introduce the Simple type reference set format, the techniques for creation of simple reference sets and provide some examples of Simple reference sets and their usage.

Simple reference sets contain only the basic information needed to define a subset. As presented in the section about the reference set design,  each member in a reference set has a referencedComponentId attribute, which is used to refer to the component that is a member of the reference set.  Within the instances of this attribute, the individual references to components are stored. The diagram below illustrates an example of a simple reference set, and illustrates how the subset members are referenced in the referencedComponentId attribute.

Simple reference set example