Report Builder specifies this constant in a SAM_ReportNotify message's lParam. Report Builder sends the SAM_ReportNotify message when it has formatted a block, but before it is actually output. When you process SAM_ReportNotify, you can check the lParam parameter value to see which part of the report Report Builder is ready to process. RPT_OutputReportHeader indicates that Report Builder is ready to process the beginning of the report. Value = 24

public const int RPT_OutputReportHeader