The CommonBitsRemover "scavenges" precision which is "wasted" by a large displacement of the geometry from the origin. For example, if a small geometry is displaced from the origin by a large distance, the displacement increases the significant figures in the coordinates, but does not affect the relative topology of the geometry. Thus the geometry can be translated back to the origin without affecting its topology. In order to compute the translation without affecting the full precision of the coordinate values, the translation is performed at the bit level by removing the common leading mantissa bits.
If the geometry envelope already contains the origin, the translation procedure cannot be applied. In this case, the common bits value is computed as zero.
If the geometry crosses the Y axis but not the X axis (and mutatis mutandum), the common bits for Y are zero, but the common bits for X are non-zero.