-All these definition block members must be present within their blocks, but only
-"ACTION" / "OBJECT" / "MAP_TYPE" must be positioned at their respective blocks'
-first line; the others may appear in whatever order and even multiple times. If
-an object or action definition block is finished, however, it cannot be
-re-defined by starting a new block with the same object type or action id.
+The map is defined by a single-line block. Its number value sets the map
+square's edge length. It must be >= 1 and <= 256:
+
+MAP_LENGTH 64
+
+The player type / species is also defined by a single line block. Its number
+value sets the player's creature's map object type by its id:
+
+PLAYER_TYPE 0
+
+All these definition block members must be present within their respective
+blocks, but only "ACTION" and "OBJECT" must be positioned at their respective
+blocks' first line; the others may appear in whatever order and even multiple
+times. If an object or action definition block is finished, however, it cannot
+be re-defined by starting a new block with the same object type or action id.