Turning inventory tracking on or off counts as one change

A product's version history counted turning inventory tracking on or off as four changes. Tracking and the three stock numbers are one thing underneath, because turning it off empties all three, so the What column filled with numbers nobody had touched.

A stock number that only travels between blank and zero while tracking changes is no longer counted. One that gains or loses a real count still is. Versions written before the fix were recalculated, so an old one reads like a new one.