-default value is @code{("%12b")}, which means that it usually
-displays @samp{Emacs:} followed by seventeen characters of the buffer
-name. (In a terminal frame, it displays the frame name instead of
-@samp{Emacs}; this has the effect of showing the frame number.) You may
-want to change this in modes such as Rmail that do not behave like a
-``normal'' Emacs.
+default value is @code{("%12b")}, which displays the buffer name, padded
+with spaces to at least 12 columns.