"4-point", "2-point", and "Legacy" PoE ?

[KB8DOA-1]

In the 1531P
Data > Switch > Power Over Ethernet options I see these choices for PoE:

"4-point", "2-point", and "Legacy"

Does anyone know what these are or where they are documented?

I cannot find anywhere in the industry that there is a reference to a "4-point" PoE.
Is Adtran making this stuff up?

[BradR · Accepted solution]

The attached image from the AOS Command Reference Guide details the different options.