Any item can be dipped into a potion of levitation to permanently reduce its weight by 20%. This uses up the potion, and it will only affect the item’s base weight, not the weight of any contents (i.e. a bag of holding thus dipped will weigh 12 + contents instead of 15 + contents).

Dipping low boots into a potion of levitation turns them into levitation boots.

Levitation from a blessed potion or an artifact allows you to use < and > to float into the air and descend at will, without the levitation timing out. This would require implementing two additional flags: one that tracks whether your levitation comes from those sources, and one that tracks whether levitation is currently suppressed due to your voluntary descending.

The potion of levitation has negative weight, and lightens your inventory load rather than weighing it down more.

Expert-cast levitation, or a blessed potion of levitation, grants flight instead of levitation.