A concept relationship style that identifies that a relationship exists between two concepts without any additional characterization of that relationship.
Sources:
NIST IR 8477
An OLIR that indicates relationships between pairs of elements without additional characterization of those relationships.
Sources:
NIST IR 8278Ar1
under Concept Crosswalk OLIR
NIST IR 8278r1
under Concept Crosswalk OLIR