Transitions of the kind internal are not shown explicitly in diagrams. Source Unified Modeling Language 2.5.1
kind = internal ... This kind of Transition can only be defined if the source Vertex is a State. Source Unified Modeling Language 2.5.1
kind = internal is a special case of a local Transition that is a self-transition (i.e., with the same source and target States), such that the State is never exited (and, thus, not re-entered), which means that no exit or entry Behaviors are executed ... Source Unified Modeling Language 2.5.1
The semantics of a Transition depend on its relationship to its source Vertex. Three different possibilities are defined, depending on the value of the Transition’s kind attribute ... Source Unified Modeling Language 2.5.1
Transitions This content has been marked as discussing an ADVANCED topic! Gallery Tutorial TRAIL: Webel's ultimate guide to Systems Modeling Language (v1) with MagicDraw/Cameo Section 01:03: UML Behavior: StateMachines quick start Slide kind UML StateMachine Diagram
An internal Transition can be taken even if the S[t]ateMachine is in one or more Regions nested within the associated State. Source Unified Modeling Language 2.5.1
internal - Implies that the Transition, if triggered, occurs without exiting or entering the source State (i.e., it does not cause a state change). This means that the entry or exit condition of the source State will not be invoked. Source Unified Modeling Language 2.5.1
TransitionKind is an Enumeration type used to differentiate the various kinds of Transitions. Source Unified Modeling Language 2.5.1