PNPPO.H

The public symbol file NTKRPAMP.PDB for the original release of Windows 10 tells that the kernel is built with the PNPPO.H header at

d:\th\minkernel\ntos\inc

and draws from it the following type definitions:

Line Number	Type
28	struct _PO_IRP_QUEUE
33	struct _PO_IRP_MANAGER
44	struct _PO_DEVICE_NOTIFY
76	struct _PO_NOTIFY_ORDER_LEVEL
85	struct _PO_DEVICE_NOTIFY_ORDER
96	enum PROFILE_STATUS
106	enum _PNP_DEVNODE_STATE
143	struct _DEVICE_NODE
406	unnamed union for OverUsed1 in _DEVICE_NODE
412	unnamed union for OverUsed2 in _DEVICE_NODE
434	unnamed struct for DockInfo in _DEVICE_NODE

The header PNPPO.H is not known in any Device Driver Kit (DDK) or Windows Driver Kit (WDK).