Classification relation type
The target is a member or subtype of the broader source class.
Directed semantics
Every direct mAtlas edge is an authored source → target assertion of this type.
Machine-readable record
/data/latest/relation-types/classification.json provides this definition and the IDs of every direct relation of this type.
A path may traverse an edge backwards for connectivity, but that never reverses the authored source-to-target assertion.