Bsc. Dim. Add or subtract

I just do programs for a company as a contractor.I have a thick headed inspector here that wants me to show him were it says that on a hole pattern that is called to abc that you add or subtract your bsc's.Say I have 5 holes in line with 1 inch spacing.the first hole is dimensioned from datum b and the remainder of the holes are 1 inch apart.He says that the way he has always done it was to zero out on each hole then check the next hole(WRONG).i'am trying to convince him how wrong he is.He wants to see it in writing.I know it has to be wrote down somewhere but I cannot find it.I've tried to show him that you check the first hole @ 1 inch report it then move your alignment 1 inch from the datum and check the next hole and report the 1 inch dim.He refuses to accept that he is convinced that you have to check the spread between holes.What I'am looking for is some thing that I can show him that shows the proper way of doing this.I've been looking but cannot find any thing that explanes this.

Thanks
lanes