In the past, the IAU has adopted standard values for some constants, primarily for use with solar system ephemerides. The constants adopted in 1976 were specifically adjusted to provide internal consistency. In each case, when constants have been adopted, the changes have reflected accuracy improvements, and the purpose has been to encourage the accomplishment of better science.

Over the past 12 years, the Working Group on Cartographic Coordinates has issued triennial reports giving the best values for the sizes and rotations for the planets and satellites. This working group now is an IAU/IAG/COSPAR working group reflecting the different organizations that have recognized the benefits of this group. This is an example of a properly functioning working group, which provides the best values on a regular basis. The IUGG also provides best estimates triennially for values of interest in geodesy and geodynamics.