We have two keys in the specification which have some meaning for the individual teams who developed it, but don't have a ton of explicitly meaning currently:

• entity: this represented the type of a component for matching against a component library
• type: this originally differentiated a component-feature from a connection-feature

There could be some need for an entity for further describing component types or to specify that two components within the list are the same by having matching entity values, but it could also be removed without any particular detriment to the system. Type doesn't really need to exist at all since all connection-features are by definition in this system straight line segments.