What are the linedef actions with "8px" for?

[Not Jabba]

I've noticed a bunch of these, and I'm not sure what it means (for instance, "Ceiling Move (8px)" in Hexen format takes the argument "Movement Amount (8px)"). What is this for? How is it different from a regular movement amount?

[Quasar]

The move amount is multiplied by 8 in order to provide a larger range, since special arguments can only hold a byte worth of data in Hexen. With the times-8 effect, you can specify an amount up to 2040 units, but only in steps of 8 units obviously, so resolution of the movement is sacrificed in exchange for range.