When you draw a symbol on a diagram in DoDAF 2, you are asked to specify a value for the Symbol Represents property. In the list for this property are all of the definition types that the symbol you are drawing can represent. This is based on what the symbol has been specified as being able to represent in the metamodel.

This is due to Inheritance in DM2 metamodel.

For example, if you draw a Resource symbol on an OV-02 Operational Resource Flow Alternative diagram, you select the definition type that the symbol represents from a list that includes Resource, and all of its subtypes (such as Performer, and so on, and all of Performer’s subtypes, such as Person, and so on).