Para 3.4.3 — MSO

3.4.3 It must be recognised that the five categories of contingencies described in the foregoing paragraph are not necessarily mutually exclusive. There may be instances of Special Contingencies being regulated by scale, or of a bill relating to Scale Regulated Contingencies requiring countersignature. Where a contingent bill falls under two or more classes, the methods of audit prescribed for each of those categories should, as far as possible, be applied to it.