To control unpacking and packing, you write a @dfn{data layout
specification}, a special nested list describing named and typed
@dfn{fields}. This specification controls length of each field to be
-processed, and how to pack or unpack it.
+processed, and how to pack or unpack it. We normally keep bindat specs
+in variables whose names end in @samp{-bindat-spec}; that kind of name
+is automatically recognized as ``risky.''
@cindex endianness
@cindex big endian