How about the moons?

Now that the IAU has drawn a line between planets and dwarf planets, and another between dwarf planets and small solar system bodies, it's time to draw a line between major and minor moons. I mean, take a look at Jupiter. Do you really want to memorize every single one of its 63 named moons? I think not. Therefore there must be a line drawn.

So let's use the same line as the one between dwarf planets and SSSBs: spheroidness. Which puts the divider down in the 4x10¹⁹ kg range, same as for dwarf planets.

Here's a list of planets (and dwarf planets which have major moons) and their major moons:

Mercury
Venus
Earth
.....Moon
Mars
Jupiter
.....Io
.....Europa
.....Ganymede
.....Callisto
Saturn
.....Mimas
.....Enceladus
.....Tethys
.....Dione
.....Rhea
.....Titan
.....Iapteus
Uranus
.....Miranda
.....Ariel
.....Umbriel
.....Titania
.....Oberon
Neptune
.....Triton
Pluto
.....Charon
"Santa"
....."Rudolph" (maybe)
"Xena"
....."Gabrielle" (maybe)

And that's all you need to know.