What is the difference between the global (90°N-S) and full (60°N-S) coverage for IMERG?

Compared to previous versions, Version 05B IMERG introduces additional coverage at the high latitudes for the complete precipitation fields in all Runs -- Early, Late, and Final.  IMERG continues to use a merged geosynchronous infrared brightness temperature analysis to both support computing the motion vectors in morphing and provide IR-based precipitation estimates.  The requisite analysis (provided by NOAA/NWS/Climate Prediction Center) covers the latitude band 60°N-S, so a "full" IMERG analysis is possible there.  At higher latitudes (in both hemispheres) both morphing and IR-based estimates are not included, so the coverage in the complete precipitation fields is "partial" -- limited to times when overpasses occur for microwave sensors and with no snow/ice on the surface.  Some of the other data fields, specifically the merged microwave estimates and the precipitation phase, were already provided for the entire globe.