C# Constants:

enum LINEMESSAGES
{
    LINE_ADDRESSSTATE = 0,
    LINE_CALLINFO = 1,
    LINE_CALLSTATE = 2,
    LINE_CLOSE = 3,
    LINE_DEVSPECIFIC = 4,
    LINE_DEVSPECIFICFEATURE = 5,
    LINE_GATHERDIGITS = 6,
    LINE_GENERATE = 7,
    LINE_LINEDEVSTATE = 8,
    LINE_MONITORDIGITS = 9,
    LINE_MONITORMEDIA = 10,
    LINE_MONITORTONE = 11,
    LINE_REPLY = 12,
    LINE_REQUEST = 13
}

VB Constants:

TODO

Notes:

From the TAPI header file. #defines for Line Messages