For aggressions, EVENTS.Certainty is the certainty of the recipient

For aggressions, EVENTS.Certainty is the certainty of the recipient

After phone discussion with Ian, 2026-05-13.

The MS Access aggression_event.ae_recipient_certainty_flag column
will need to be normalized to 'Y' and 'N' in the "clean" schema.
NULL and N means false, Y and X means true.  And some other
illegitimate values exist.