C# Definition:

/// <summary>
///     Specifies a raster-operation code. These codes define how the color data for the
///     source rectangle is to be combined with the color data for the destination
///     rectangle to achieve the final color.
/// </summary>
private enum TernaryRasterOperations : uint {
    /// <summary>dest = source</summary>
    SRCCOPY = 0x00CC0020,
    /// <summary>dest = source OR dest</summary>
    SRCPAINT = 0x00EE0086,
    /// <summary>dest = source AND dest</summary>
    SRCAND = 0x008800C6,
    /// <summary>dest = source XOR dest</summary>
    SRCINVERT = 0x00660046,
    /// <summary>dest = source AND (NOT dest)</summary>
    SRCERASE = 0x00440328,
    /// <summary>dest = (NOT source)</summary>
    NOTSRCCOPY = 0x00330008,
    /// <summary>dest = (NOT src) AND (NOT dest)</summary>
    NOTSRCERASE = 0x001100A6,
    /// <summary>dest = (source AND pattern)</summary>
    MERGECOPY = 0x00C000CA,
    /// <summary>dest = (NOT source) OR dest</summary>
    MERGEPAINT = 0x00BB0226,
    /// <summary>dest = pattern</summary>
    PATCOPY    = 0x00F00021,
    /// <summary>dest = DPSnoo</summary>
    PATPAINT = 0x00FB0A09,
    /// <summary>dest = pattern XOR dest</summary>
    PATINVERT = 0x005A0049,
    /// <summary>dest = (NOT dest)</summary>
    DSTINVERT = 0x00550009,
    /// <summary>dest = BLACK</summary>
    BLACKNESS = 0x00000042,
    /// <summary>dest = WHITE</summary>
    WHITENESS = 0x00FF0062
}

VB.NET Definition:

''' <summary>
'''     Specifies a raster-operation code. These codes define how the color data for the
'''     source rectangle is to be combined with the color data for the destination
'''     rectangle to achieve the final color.
''' </summary>
Private Enum TernaryRasterOperations As UInteger
    ''' <summary>dest = source</summary>
    SRCCOPY = &Hcc0020
    ''' <summary>dest = source OR dest</summary>
    SRCPAINT = &Hee0086
    ''' <summary>dest = source AND dest</summary>
    SRCAND = &H8800c6
    ''' <summary>dest = source XOR dest</summary>
    SRCINVERT = &H660046
    ''' <summary>dest = source AND (NOT dest)</summary>
    SRCERASE = &H440328
    ''' <summary>dest = (NOT source)</summary>
    NOTSRCCOPY = &H330008
    ''' <summary>dest = (NOT src) AND (NOT dest)</summary>
    NOTSRCERASE = &H1100a6
    ''' <summary>dest = (source AND pattern)</summary>
    MERGECOPY = &Hc000ca
    ''' <summary>dest = (NOT source) OR dest</summary>
    MERGEPAINT = &Hbb0226
    ''' <summary>dest = pattern</summary>
    PATCOPY = &Hf00021
    ''' <summary>dest = DPSnoo</summary>
    PATPAINT = &Hfb0a09
    ''' <summary>dest = pattern XOR dest</summary>
    PATINVERT = &H5a0049
    ''' <summary>dest = (NOT dest)</summary>
    DSTINVERT = &H550009
    ''' <summary>dest = BLACK</summary>
    BLACKNESS = &H42
    ''' <summary>dest = WHITE</summary>
    WHITENESS = &Hff0062
End Enum

Notes:

None.