* doc/lispref/display.texi (Face Attributes): Fix the description
of negative width of the ':box' attribute. (Bug#26920)
This way you can explicitly specify all aspects of the box. The value
@var{width} specifies the width of the lines to draw; it defaults to
1. A negative width @var{-n} means to draw a line of width @var{n}
-that occupies the space of the underlying text, thus avoiding any
-increase in the character height or width.
+whose top and bottom parts occupy the space of the underlying text,
+thus avoiding any increase in the character height.
The value @var{color} specifies the color to draw with. The default is
the foreground color of the face for simple boxes, and the background