   @moduledoc """
   Module responsible for doing IO. Many functions in this
   module expects an IO device and an io data encoded in UTF-8.
+  Use the bin* functions if the data is binary, useful when
+  working with raw bytes or when no unicode conversion should
+  be performed.
 
   An IO device must be a pid or an atom representing a process.
   For convenience, Elixir provides `:stdio` and `:stderr` as

  Gets a number of bytes from the io device. If the
  io device is a unicode device, `count` implies
  the number of unicode codepoints to be retrieved.
  Otherwise, `count` is the number of raw bytes to be retrieved. 
  It returns:

  * `data` - The input characters.

    with many bytes (Elixir's default representation);

  * A list of binaries or a list of char lists (as described above);

  """

