It might be useful to add a custom type so that systems wanting to exchange entities that are not military or ADS-B can define a custom categorization type.

CategorizationData provides information on how to draw an entity, however systems might want to exchange entities for purposes other than display. Therefore having a CategorizationData type that indicates that the entity is not to be drawn might be useful.

In the DDS/IDL DataPayload PSM struct EntityPayload needs an @key decorator on the entityPayloadBase attribute so that each specialisation is keyed by id

Section 7.3.18 the description for GeodeticPosition specifies that "The Angle unit as well as the projection are set by the Group.". However for a WGS84 position this would idiomatically be expected to be in degrees but elsewhere in a TEX entity a system implementer would possibly want to use SI angle units (radians) for other angles on an entity.

We could introduce an additional GeodeticAngleUnit attribute to the metadata to allow geodetics to use different units to other angles in an entity.

The ADSBCategorizationData class has no attributes which is peculiar. As a consequence there is no struct defined in the IDL and the type is not present in the CategorizationData union.

This should probably either have some attributes added or be removed.