Activity Explorer logs a DLP rule match event each time any DLP rule condition is met on a file.

File1 matches Rule11 and Rule12 → 2 events

File2 matches Rule21 and Rule22 → 2 events

File3 matches Rule11 and Rule22 → 2 events

Total events in Activity Explorer = 2 + 2 + 2 = 6.

Microsoft notes that Activity explorer shows granular DLP activities such as policy rule matches per item.

The DLP incidents report aggregates by policy match per item, not by each rule in that policy. Multiple rules from the same policy on the same item count as one incident; if different policies match the same item, each policy creates its own incident.

File1: Rules from DLP1 only → 1 incident

File2: Rules from DLP2 only → 1 incident

File3: One rule from DLP1 and one from DLP2 → 2 incidents

Total incidents = 1 + 1 + 2 = 4.