Ken,
It's a CCR rule, not 944 Spec:
17.8 Minimum Weight
Each driver shall be given a standard five (5.0) pound leeway under the minimum published weight for their car
during the first time (voluntary or not) the car is weighed for that event. After the initial weighing, the competitor
must meet the exact published weight with zero (0.0) pounds leeway for the remainder of that event. This
policy should compensate for any discrepancies between scales, margin of error, and imperfections in ground
surfaces. No other tolerance will be given.