checkcentering is a little program that analyzes XDS_ASCII.HKL for possible centering. Concerning centering, it does a similar analysis as pointless, but also suggests how to convert I2 centering to C2 centering.
The reason why this may be useful is that sometimes some weak reflections make the lattice appear as primitive, when it is really centered. Or, a primitive lattice looks centered at low resolution.
The program should be run in a folder with XDS_ASCII.HKL.