element says how to display the character code @var{n}. The value
should be @code{nil} or a vector of glyph values (@pxref{Glyphs}). If
an element is @code{nil}, it says to display that character according to
-the usual display conventions (@pxref{Usual Display}).
+the usual display conventions (@pxref{Usual Display}). Note that the
+display table has no effect on the tab and newline characters; they are
+always displayed as whitespace in their usual special fashion.
The remaining five elements of a display table serve special purposes,
and @code{nil} means use the default stated below.