INTERFACE_TYPE - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTIOAPI_H

// Other types

typedef enum _INTERFACE_TYPE
{
    InterfaceTypeUndefined = -1,
    Internal = 0,
    Isa = 1,
    Eisa = 2,
    MicroChannel = 3,
    TurboChannel = 4,
    PCIBus = 5,
    VMEBus = 6,
    NuBus = 7,
    PCMCIABus = 8,
    CBus = 9,
    MPIBus = 10,
    MPSABus = 11,
    ProcessorInternal = 12,
    InternalPowerBus = 13,
    PNPISABus = 14,
    PNPBus = 15,
    Vmcs = 16,
    ACPIBus = 17,
    MaximumInterfaceType
} INTERFACE_TYPE, *PINTERFACE_TYPE;

#endif

View code on GitHub

This enumeration is documented in Windows Driver Kit.