http://portal.fciconnect.com/Comergent//fci/drawing/87583.pdf

If you go to the foot print, there are values in the rectangles with A B and X Y. What do those numbers represent?

 

http://en.wikipedia.org/wiki/Datum_reference

 

Then what do the numbers mean? That the position could vary by .25mm diameter with respect to the axis it references?

 

http://en.wikipedia.org/wiki/Geometric_dimensioning_and_tolerancing

 

Thanks! That makes sense now!