Step (STP) files save footsteps, but don't save body keyframes.
The STP file format is an ASCII format that enables developers to write programs that generate step files for biped motion. The online document stp.rtf, provided with character studio in the ..\cstudio\docs directory, describes the STP format.
Select the biped to animate via saved footsteps, then go to the
Motion panel.
(Load File).
The footsteps are loaded onto the biped, and new default keys are generated to match the footsteps.
Select the biped whose footsteps you want to save, and go to the
Motion panel.
(Save File).