Calculated reference attribute instances cannot be deleted

[JonP]

For my future benefit and for anyone who may be experiencing this, I hereby memorialize...

I don't know if this a bug or a feature, but I just re-learned that if you set a reference attribute as "Calculated", when you add a delete operation for reference instances, the delete button does not appear in the form. I thought that "Calculated" only pertained to updating (which is according the user guide), but that setting also prohibits deletion as well.