What do the different shaped icons on the Satellite polar plot of Quantum Display represent?

The Polar plot displayed in Quantum uses 6 different shaped icons each type of shape represent a different type of satellite constellation.

Satellite polar plot

These shapes and their representations are as follows:

Circle:  GPS satellite

Square: GLONASS satellite

Diamond: Galileo satellite

Triangle: Beidou satellite 

Octagon: QZSS satellite

The satellite shaped icons: represent the Inmarsat Communication satellite (25E, IOR, etc.)