[Proj] Geod: I need a little guide

[Paul Selormey]

Hello All,
I need a little guide on the geod program, even the command options.

In particular, any guide on the implementations? Is it based the
WGS84 EGM96 model?

Anyone knows the EGM96 binary file format in Geotrans?
(the "egm96.grd" file) - I managed some format after reading
the Geoid conversion sources, but do not know if it is the complete/true
picture.

Best regards,
Paul.