How the sections fit together

Most sections stand alone, but many numbers in them point into another section, and a few sections decide the size or the meaning of others.

Which sections point into which

A number in	Points at
`SPRP`, `FORC`, `MRGN`, `UNIS` and `UNIx`, `SWNM`, `WAV`, and the actions of `TRIG` and `MBRF`	A string in `STR`, or `STRx` on a Remastered map that has one. String numbers count from 1, and 0 means none.
A condition or action of `TRIG`	A location of `MRGN`, counted from 1: location 1 is the first record, and Anywhere, the 64th record, is location 64.
The Create Unit with Properties action	A slot of `UPRP`, counted from 1.
`UPUS`	The slots of `UPRP`, in the same order.
A `UNIT` record's linked unit	Another `UNIT` record, by its serial number: an add-on and the building it belongs to, or two nydus canals.
`IOWN`	The same twelve player slots as `OWNR`; editors show one and the game reads the other.
`MTXM` and `TILE`	Tile groups of the tileset `ERA` names.
`ISOM`	The values of the tileset `ERA` names.
A `DD2` record	A doodad of the tileset `ERA` names. The doodad's tiles are in `MTXM` and its sprite, if it has one, in `THG2`.

DIM sets the size of four sections: MTXM and TILE hold two bytes per tile, MASK one, and ISOM (width ÷ 2 + 1) × (height + 1) × 8 bytes. VER decides which of the settings tables the game reads; see Revisions.