Kernel

Prefix	Subsystem	Example
Nt or Ze	System call interface	NtOpenFile/ZwOpenFile
Se	Security Reference Monitor	SeAccessCheck
Ob	Object Manager	ObReferenceObjectByHandle
Ps	Process and thread manager	PsGetCurrentProcess
Cm	Configuration manager	CmRegisterCallback
Mm	Memory manager	MmMapIoSpace
Io	Input/output manager	IoCreateFile
Ci	Code integrity	CiValidateFileObject