UML23 — Section: 15.3.8

It is unclear what exactly is a path in the context of history pseudo states. For example: "Entry actions of states entered on the path to the state represented by a shallow history are performed." Is it the shortest path? The history path? What happens if the history state isn't the first state after the initial state, but located somewhere in the middle of the statemachine?

The word 'Path' has raised ambiguity with respect to how the history state will restore the active state configuration. There is only one way that the history will restore the active state, and that is through an implicit direct path from the history state to the last active state being reactivated (as though a transition is drawn directly from H to the last active substate). It in no way implies a state-by-state approach. (e.g. a path from the initial state to the last active state)