Another type of validation would be a "closed loop" validation that would allow validation of integrity of events that touch each other in the network.
An example of this is the functional classification system for an example. As a general rule but with certain exceptions like state borders/extents, major airports, parks, and intermodal facilities, highways with functional classification greater than local are typically connected to other highways with functional classification greater than local without dangles or "gaps" across null or local functional classification values. It would be very similar to event on event, but it is more selectively looking for events touching other events, and ensuring there are no event gaps within subset values of events.