OPEN-17
An unrecognised edge type is a save-time error.
Superseded by OPEN-32. A ruling is never rewritten; this one stands as it was written and a later one takes its place.
What was open
A declared edge type the implementation did not recognise fell through to the default, so a typo silently became an ordering edge.
Decision
A non-empty declared edge type that the implementation does not recognise is a validation error at save. An absent or empty declaration keeps the documented fallback, which is a different thing from a declaration that is present and wrong. A declared enumeration is validated at the door it is declared at.