Dutchbird, the "Official Shifted" is the official version that when used on a non chinese GPS unit, cause all the co-ordinates to be shifted by about 500-600m.

The Venus version has been modified so that the co-ordinates show the true points and can be used with all non chinese GPS units.

Basically, unless you bought your GPS in China, Venus is the map version you want to be using.

There's quite a good explanation under:

City Navigator China NT 2011.40 - English+Venus Series Shift Corrected version
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