Correction for the t0 constants of the forward RPCs

It is argued that the `neutral' t0 calibration is appropriate for the forward RPCs while it is beset with too large systematic uncertainties for the barrel RPCs. The toy Monte Carlo calculation of the correction is described that moves the `50% point' on the rising slope of the time distribution of `neutral' hits in the forward RPCs to the theoretical point that would be measured in an infinitely small pad at the pad's centre and that serves for the absolute normalisation of time of flight.