I've been running astrometry for the MPC for 10 years now and it's still unclear to me just what the MPC is looking for in the way of coverage.  My understanding is that they desire the observations to be on "critical list objects."  And they do post a critical list at  https://www.minorplanetcenter.net/iau/Ephemerides/CritList/Soft06CritList.txt

This data can be converted from .txt format to .dat format, but the .dat file isn't Guide compatible.

What exactly is the MPC's definition of "critical list objects" 

Does anyone know which MPC lists are being tapped by the MPEC Sort routine?  

And am I correct in assuming that the main function of this program is to convert data into Guide format?

Pete (feeling really ignorant)

p.s.  Present workaround is to go out and turn on the observatory Win 7 computer  Run MPEC Sort & download go Guide 9.  Then copy the resulting MPCORB.DAT file with the critical list objects onto a USB drive, bring the thumb drive into the house and copy the .DAT file into Guide 9.  And finally run Guide 9 to selectively choose a dozen targets for the coming night.  Lot of extra effort :-(