I have not yet seen a pi or pi-related board that supports 802.3af right into the jack and right out of the box. A few support surprisingly large add-on boards

I have not yet seen a pi or pi-related board that supports 802.3af right into the jack and right out of the box. A few support surprisingly large add-on boards that connect to the GPIO pins and to a set of pins near the RJ45 so you can still use the built in jack for data and power. You can always use a non-standard or even standard injector/tap but that's probably not what you're after. I have a side project where I disassembled a 802.3af tap and USB ethernet board and wired it all directly into a PiZero. The POE tap and USB ethernet boards are pretty small internally. The POE tap has a cat5-like header that comes off I just wired straight into the pads the ethernet controller was using while removing the RJ45 plug on the board. https://imgur.com/0gBj23G https://imgur.com/0gBj23G