NO-INTERFERENCE AREA
  1. (zone) from R6 Solo to OT III one does not do anything except keep the pc winning for R6 Solo to OT III. This is the critical band of the gradation chart. From R6 to OT III you have a closed band for other major actions. (HCOB 23 Dec 71)
  2. where drugs have not been handled or only partially have been handled, the no interference zone rule is waived. (HCOB 31 May 74)

Technical Dictionary