@defvar tool-bar-border
This variable specifies the height of the border drawn below the tool
-bar area. An integer value specifies height as a number of pixels.
+bar area. An integer specifies height as a number of pixels.
If the value is one of @code{internal-border-width} (the default) or
@code{border-width}, the tool bar border height corresponds to the
corresponding frame parameter.
@item :key-sequence @var{keys}
@var{keys} is a hint for speeding up Emacs's first display of the
-menu. It should be nil if you know that the menu item has no keyboard
+menu. It should be @code{nil} if you know that the menu item has no keyboard
equivalent; otherwise it should be a string or vector specifying a
keyboard equivalent for the menu item.
@item :selected @var{selected}
@var{selected} is an expression; the checkbox or radio button is
-selected whenever the expression's value is non-nil.
+selected whenever the expression's value is non-@code{nil}.
@item :help @var{help}
@var{help} is a string describing the menu item.