The pointer to this section is at offset +40.

 +0 500 RECORDs of 8 bytes each; Mine fields
                 +0     WORD    X
                 +2     WORD    Y
                 +4     WORD    Radius. Zero if the minefield has been
                                swept. All other information remains in
                                this minefield slot until the slot is
                                re-used for a new minefield.
                 +6     WORD    Owner.
                                 0      empty record
                                 1..11  Normal minefield belonging to
                                        race 1..11
                                 12     Crystalline Web mine field.
                                Note that this does not allow transmission
                                of web minefields that do not belong to the
                                Crystals. Non-Crystalline webs are sent as
                                normal mines (1..11).
                This section contains not only the minefields the player
                scanned this turn, but also all of his own minefields. This
                implicitly provides information about minefields that were
                swept completely.
 +? 600 BYTEs   Ion storms, 50 records of 12 bytes each
                 +0     WORD    X
                 +2     WORD    Y. Note that THost sometimes generates
                                storms with negative coordinates.
                 +4     WORD    Radius
                 +6     WORD    Voltage in MeV
                                 0      non-existent
                                 even   weakening storm
                                 odd    growing storm
                 +8     WORD    Warp
                +10     WORD    Heading in degrees
                see also GREY.HST below.
 +?  50 RECORDs of 4 bytes each: Explosions
                 +0     WORD    X (0 = non-existent)
                 +2     WORD    Y
                THost generates an explosion entry for every ship that
                exploded due to excess damage in battle or after a mine
                hit. PHost only generates these entries for ships
                exploding after a mine hit.
 +? 682 BYTEs   Contents of RACE.NM. RACE.NM remains unchanged if this
                field is empty (only spaces).
 +? 7800 BYTEs  Contents of UFO.HST, filtered
 +?   4 BYTEs   Signature "1211", if all visual contacts fit into the
                normal TARGETx.DAT file, "1120" otherwise. These numbers
                appear to be literals, not some strange flags.
--- Additional Visual Contacts ---
 +?     DWORD   Number of contacts.
 +?   n RECORDs of 34 bytes each.
                 +0     WORD    Id Number
                 +2     WORD    Owner
                 +4     WORD    Warp
                 +6     WORD    X location
                 +8     WORD    Y location
                +10     WORD    Type of hull
                +12     WORD    Heading in degrees, 0=North, 90=East,
                                180=South, 270=West, -1=unknown
                +14  20 BYTEs   Ship name, encrypted
                                  FOR i:=1 TO 20 DO
                                    Encrypted[i] := Original[i] XOR (155-i)
                Note that, except for the ship name, this is exactly a
                TARGETx.DAT record.

LEECHx.DAT

If the value at +44 is non-zero, it points to the following data:

 +0     DWORD   Size of LEECHx.DAT
 +4   n BYTEs   Contents of LEECHx.DAT

You only need to place a file named LEECHx.DAT in the Host directory, and the Host will send it to the players. Winplan's UNPACK will unpack it to the game directory. This file is not used otherwise.

Extended Ufo database

In version "01" RSTs, the value at +48 points to the following data:

 +0     WORD    Total number of Ufos. The minimum value is 100, as there
                are already 100 Ufo records in the standard Winplan
                section.
 +2   n RECORDs of 78 bytes each: the Ufos. This field contains the Ufos
                from Id 101 onwards. Thus, the extended Ufo database stores
                100 Ufos less than specified in the WORD above.
This is a testing version.
It may be incomplete, and have more bugs (or features) than the public live version at planetscentral.com.