According to Meyer, the quarterstaff is the basis of all long weapons.

Oberhut – High Guard

In the high guard position yourself thus: stand with your left foot forward, and hold your staff with the tail at your chest, so that the point stands straight up toward the sky. Now as you execute this straight before you, so you shall also do it on both sides. And although you shall always keep your left foot forward, yet you must not let your feet get too far apart, so that you can always have a step forward with the left foot.

I don’t have a picture of this guard, but here is a halberd stance that appears to be of the same guard. Note the wide stance, which seems to be contrary to Meyer’s recommendations.

Underhut – Low Guard

Do it thus: stand with your left foot forward again, hold your staff with the butt on your flank, and with the tip extended before you on the ground. If you hold the butt on your right flank, then it doesn’t matter whether you hold or send the tip extended to the left or right or straight before you: you can vary how you extend it, either according to how he attacks, or according to what techniques you intend to use.

Again, I’m using a halberd plate to illustrate this guard.

Nebenhut – Side Guard

For this, position yourself thus: stand with your right foot forward, hold your staff with the midpart on your left hip, so that the butt extends toward the opponent, and the tip behind you; thus present your right side fully to him, as shown by the figure on the lower right in Image A.

This looks more like Zornhut on the left to me.

Mittelhut – Middle Guard

The Middle Guard is the Straight Parrying before the opponent, from which one mostly fights.

This is my best guess as to what he means.

Steürhut – Rudder Guard

In this one, position yourself thus: stand with your left foot forward and hold your staff with the tip on the ground in front of your left foot, and the butt up before your face with your arms extended, as you can see in the other figure on the left in the same image [A]. You can also do this guard thus: stand with your right foot forward, and hold your staff behind you, again with the tip on the ground; thus you are positioned for the stroke.