The term is mostly historical. Do not buy a PIH006 sub patched unit expecting anything other than a modchip-based solution. If you already own one, your path to custom firmware is: soldering station, microscope, Picofly chip, and patience.
Expected output: PIH006:YES or sub_patched=1 . If you see sub_patched=0 , you are vulnerable. pih006 sub patched
Who is the (developers, casual users, or a private group)? The term is mostly historical