This record is the same as used by PHost for regular minefield reports.
WORD Minefield Id WORD X WORD Y WORD Owner DWORD Mine units WORD Type (1=Web, 0=normal) WORD (reserved for controlling planet Id; sent as zero) WORD Report type (0=laid, 1=swept, 2=scanned)
Caveat: like the messages, these records report status after the lay/sweep action. Mine decay will happen afterwards and cause the field to shrink. You should have some ships at "Mine Sweep" to get precise reports from PHost.
