/*N SLOG_EXTRA_RECDEFS

    Notes on the Addition of Extra Record Definitions
        This note is to clarify the usage of SLOG_RDEF_XXX() routines
        especially while the user wants to add extra record definitions
        to the logfile when the process of addition of interval records 
        to the logfile has been started, for instance if one needs to
        add user marker interval records.

        Under normal circumstances, the record definition table is created
        by first opening the section of the logfile for storing the table
        using SLOG_RDEF_Open().  Then add the record definition using
        SLOG_RDEF_AddRecDef() and close the table section by
        SLOG_RDEF_Close().

        In the case that the logfile involves interval records whose
        interval type are NOT known until the process of inserting
        of the interval records to the logfile has been started, one 
        should open the SLOG_RDEF_Open().  Then add the known record 
        definitions using SLOG_RDEF_AddRecDef().  However, one should
        NOT call SLOG_RDEF_Close() to close the table section.  Instead,
        SLOG_RDEF_SetExtraNumOfRecDefs() should be called to set
        the extra number of record definition entries needed( the
        number can be greater than what one actually needs ).  Then
        when user encounters a new interval record type, 
        SLOG_RDEF_AddExtraRecDef() can then be called to add the new
        interval record type to the record definition table.  This
        has to be done before adding the interval record to the logfile
        using SLOG_Irec_ToOutputStream() which does NOT allow interval
        record of with unknown interval type to the record definition
        table.

.n

N*/
