Datum Shift

I received a report from a vendor where they are showing everything on a part 100% in tolerance. I have checked the part myself and show quite a few things out of tolerance. On their report I noticed a term "DATUM SHIFT" and some variables "X,Y,Z", etc. just before each dimension is reported. My question is this, What exactly is "DATUM SHIFT" and what is it doing? Is there some kind of data manipulation going on here?

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cmm-measurer over 14 years ago

I guess I was pretty vague on the MMC thing. The feature hole and two datum holes (B and C) are at MMC. Thr vendor sent me reports using the PC-DMIS text only format. I had never seen this type of report before so I did not understand what the Datum Shift Rotation arguments were doing, The lines for the Datum shift don't even show on my reports when I do the PC-DMIS text reports, so I guess it threw me. I use another software to create my formal reports and position dimensions use a position/bonus tolerance calculator. So I don't identify datums when reporting features, just their size and location relative to those datums.
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cmm-measurer over 14 years ago

I guess I was pretty vague on the MMC thing. The feature hole and two datum holes (B and C) are at MMC. Thr vendor sent me reports using the PC-DMIS text only format. I had never seen this type of report before so I did not understand what the Datum Shift Rotation arguments were doing, The lines for the Datum shift don't even show on my reports when I do the PC-DMIS text reports, so I guess it threw me. I use another software to create my formal reports and position dimensions use a position/bonus tolerance calculator. So I don't identify datums when reporting features, just their size and location relative to those datums.
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