To understand the format of Preferences files, you must be familiar with
IFF file standard (see the Amiga ROM Kernel Reference Manual: Devices for
the complete specification).

In general all Preferences files are stored in the IFF format with a type
of PREF (see the exceptions noted below).  Each file contains at least two
Chunks, a header Chunk and a data Chunk.

 The Header Chunk    The Data Chunk