These commands manipulate the absolute and relative proper motions. These data are not yet very numerous, but their importance will grow with the results of Hipparcos. The option -info is interesting: it displays the information collected by van Leeuwen on proper motion studies. The argument can be a reference number or a cluster name.
> apm -info 180 display the information for reference 180
> apm -info NGC 2682 display the information for NGC 2682