POP.H

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

d:\th\minkernel\ntos\po

and draws from it the following type definitions:

Line Number	Type
536	struct _POP_IRP_DATA
554	unnamed struct for Device in _POP_IRP_DATA
561	unnamed struct for System in _POP_IRP_DATA
574	struct _POP_IRP_WORKER_ENTRY
1101	struct _POP_RW_LOCK
1130	enum _POP_DEVICE_IDLE_TYPE
1135	struct _POP_COOLING_EXTENSION
1151	struct _DEVICE_OBJECT_POWER_EXTENSION
1174	unnamed union for Specific in _DEVICE_OBJECT_POWER_EXTENSION
1175	unnamed struct for Disk in Specific in _DEVICE_OBJECT_POWER_EXTENSION
1300	struct _POP_POLICY_DEVICE
1630	struct _POP_THERMAL_TELEMETRY_TRACKER
1642	struct _POP_THERMAL_ZONE
1859	struct _POP_SHUTDOWN_BUG_CHECK
1871	enum _POP_IO_STATUS
1877	struct _POP_IO_INFO
1894	struct _POP_PER_PROCESSOR_CONTEXT
1929	struct _POP_HIBER_CONTEXT
2126	struct _POP_DEVICE_SYS_STATE
2180	struct _POP_POWER_ACTION
2234	unnamed struct for WakeAlarm array in _POP_POWER_ACTION
2273	struct _POP_CURRENT_BROADCAST
2510	union _PPM_POLICY_SETTINGS_MASK
2777	struct _PPM_ENGINE_SETTINGS
3011	struct _POP_POWER_SETTING_VALUES

4521	struct _POP_CPU_INFO
5325	struct _POP_PPM_PROFILE
7799	struct _POP_F_WORK_ORDER_WATCHDOG_INFO
7805	struct _POP_FX_WORK_ORDER
7819	struct _POP_FX_PLUGIN
7831	struct _POP_FX_IDLE_STATE
7857	union _POP_FX_COMPONENT_FLAGS
7889	struct _POP_FX_PROVIDER
7894	struct _POP_FX_DEPENDENT
7917	struct _POP_FX_ACCOUNTING
7927	struct _POP_FX_PERF_SET
7952	union _POP_FX_PERF_FLAGS
7975	struct _POP_FX_PERF_INFO
7992	struct _POP_FX_COMPONENT
8198	struct _POP_FX_DRIVER_CALLBACKS
8226	union _POP_FX_DEVICE_STATUS
8309	struct _POP_FX_DEVICE

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