Parameter=character-strings

    Specifies one or more character strings that are concatenated
    together and passed to the callback routine upon startup.

    For each table that is associated with a user-supplied callback
    routine, the callback routine is called with two parameters: the
    length of the Parameter record and a pointer to the Parameter
    record. The binary format and contents of this record are shown
    in Parameter Record Contents.

    Table 21 Parameter Record Contents

                 Length (in
    Field        bytes)       Contents

    ACTION       1            "P"
    RELATION     31           Relation name
    RECORD_TYPE  4            Zero
    DATA_LEN     2            Length of parameter string
    NBV_LEN      2            Zero
    LDBK         8            Zero
    START_TAD    8            Zero
    COMMIT_TAD   8            Zero
    TSN          8            Zero
    DATA         ?            Variable length parameter string
                              content