Morrowind Mod:Mod File Format/TES3

The TES3 record stores the master or plugin file's header data. This includes: author name, description, file version, master files, and the size of the master files.

C	Field	Type/Size	Info
+	HEDR	struct (300 bytes)	Header float32 - Version (1.2 for Morrowind, 1.3 for Bloodmoon and Tribunal) uint32 - Flags 0x1 = file should be treated as a master, regardless of the file extension char[32] - Company name string char[256] - File description uint32 - Number of records after this one
*	MAST	zstring	Master filename Each pair of MAST/DATA subrecords represents a single master of the mod file. Master files are listed in load order at the time the mod was saved.
	DATA	uint64	Size of the previous master file in bytes (used for version tracking of plugin)