C# Definition:

/// <summary>Enumeration containing flags for a raw input device.</summary>
[Flags()]
public enum RawInputDeviceFlags
{
    /// <summary>No flags.</summary>
    None = 0,
    /// <summary>If set, this removes the top level collection from the inclusion list. This tells the operating system to stop reading from a device which matches the top level collection.</summary>
    Remove = 0x00000001,
    /// <summary>If set, this specifies the top level collections to exclude when reading a complete usage page. This flag only affects a TLC whose usage page is already specified with PageOnly.</summary>
    Exclude = 0x00000010,
    /// <summary>If set, this specifies all devices whose top level collection is from the specified usUsagePage. Note that Usage must be zero. To exclude a particular top level collection, use Exclude.</summary>
    PageOnly = 0x00000020,
    /// <summary>If set, this prevents any devices specified by UsagePage or Usage from generating legacy messages. This is only for the mouse and keyboard.</summary>
    NoLegacy = 0x00000030,
    /// <summary>If set, this enables the caller to receive the input even when the caller is not in the foreground. Note that WindowHandle must be specified.</summary>
    InputSink = 0x00000100,
    /// <summary>If set, the mouse button click does not activate the other window.</summary>
    CaptureMouse = 0x00000200,
    /// <summary>If set, the application-defined keyboard device hotkeys are not handled. However, the system hotkeys; for example, ALT+TAB and CTRL+ALT+DEL, are still handled. By default, all keyboard hotkeys are handled. NoHotKeys can be specified even if NoLegacy is not specified and WindowHandle is NULL.</summary>
    NoHotKeys = 0x00000200,
    /// <summary>If set, application keys are handled.  NoLegacy must be specified.  Keyboard only.</summary>
    AppKeys = 0x00000400
}

VB.NET Definition:

<Flags()> _
Public Enum RawInputDeviceFlags
    ''' <summary>No flags.</summary>
    None = 0
    ''' <summary>If set, this removes the top level collection from the inclusion list. This tells the operating system to stop reading from a device which matches the top level collection.</summary>
    Remove = &H1
    ''' <summary>If set, this specifies the top level collections to exclude when reading a complete usage page. This flag only affects a TLC whose usage page is already specified with PageOnly.</summary>
    Exclude = &H10
    ''' <summary>If set, this specifies all devices whose top level collection is from the specified usUsagePage. Note that Usage must be zero. To exclude a particular top level collection, use Exclude.</summary>
    PageOnly = &H20
    ''' <summary>If set, this prevents any devices specified by UsagePage or Usage from generating legacy messages. This is only for the mouse and keyboard.</summary>
    NoLegacy = &H30
    ''' <summary>If set, this enables the caller to receive the input even when the caller is not in the foreground. Note that WindowHandle must be specified.</summary>
    InputSink = &H100
    ''' <summary>If set, the mouse button click does not activate the other window.</summary>
    CaptureMouse = &H200
    ''' <summary>If set, the application-defined keyboard device hotkeys are not handled. However, the system hotkeys; for example, ALT+TAB and CTRL+ALT+DEL, are still handled. By default, all keyboard hotkeys are handled. NoHotKeys can be specified even if NoLegacy is not specified and WindowHandle is NULL.</summary>
    NoHotKeys = &H200
    ''' <summary>If set, application keys are handled.  NoLegacy must be specified.  Keyboard only.</summary>
    AppKeys = &H400
End Enum

Notes:

None.