Untitled

WhilePrintingRecords;
Shared StringVar FirstPrevFlag := "No";

If InStr({YourField}, "Prev.") > 0 Then
    If FirstPrevFlag = "No" Then
        FirstPrevFlag := "Yes";
        " " + {YourField}
    Else
        {YourField}
    End If
Else
    {YourField}
End If