I believe the documentation on PIPL in the Photoshop SDK is incomplete.

The PIPL file starts with the Property List structure, and the first field of that structure is the 4-byte version number, which is 0. However, when I load a Photoshop filter plugin into software that allows viewing and extracting of resources in an EXE or DLL files, and I extract the PIPL resource, and view it in a hex editor. I find there are 2 bytes BEFORE the 4-byte version field. These first 2 bytes are 0x01 0x00. And nothing in the Photoshop SDK would lead me to believe that there should be any data before the version field of the Property List structure. Can someone here explain what those first 2 bytes in the resource are supposed to be?