The UML «Trace» and SysML Trace can't be applied to a Slot as target (because Slot is just an Element, not a NamedElement).
Webel: A plain Dependency that is not stereotyped is always strictly timed-ordered; the supplier (target) must exist before the client (source).
Context blocks are typically the owner of the first property in the path of properties, but can be specializations of the owner to limit the scope of the relationship. Source OMG Systems Modeling Language (SysML) 1.6
The DirectedRelationshipPropertyPath stereotype based on UML DirectedRelationship enables directed relationships to identify their sources and targets by a multi-level path of properties accessible from context blocks for the sources and targets. Source OMG Systems Modeling Language (SysML) 1.6
The Trace stereotype specializes UML4SysML Trace and DirectedRelationshipPropertyPath to enable traces to identify their sources and targets by a multi-level path of accessible properties from context blocks for the sources and targets. Source OMG Systems Modeling Language (SysML) 1.6
When the «rate» stereotype is applied to an activity edge, it specifies the expected value of the number of objects and values that traverse the edge per time interval, that is, the expected value rate at which they leave the source node and arrive at ... Source OMG Systems Modeling Language (SysML) 1.6
MagicDraw/Cameo: you can make relationships between elements that are not visible in one diagram using the Relations section of the specification dialog for an element
The Refine stereotype specializes UML4SysML Refine and DirectedRelationshipPropertyPath to enable refinements to identify their sources and targets by a multi-level path of accessible properties from context blocks for the sources and targets. Source OMG Systems Modeling Language (SysML) 1.6
A Vertex is an abstraction of a node in a StateMachine graph. It can be the source or destination of any number of Transitions. Source Unified Modeling Language 2.5.1
Connection point references are sources/targets of Transitions implying exits out of/entries into the submachine StateMachine referenced by a submachine State. Source Unified Modeling Language 2.5.1
Connection point references of a submachine State can be used as sources/targets of Transitions. They represent entries into or exits out of the submachine StateMachine referenced by the submachine State. Source Unified Modeling Language 2.5.1
A ConnectionPointReference represents a point on the submachine State at which a Transition either terminates or originates. That is, they serve as targets for incoming Transitions to submachine States, as well as sources for outgoing Transitions ... Source Unified Modeling Language 2.5.1