%p -- print percent of buffer above top of window, or Top, Bot or All.
%P -- print percent of buffer above bottom of window, perhaps plus Top,
or print Bottom or All.
- %m -- print the mode name.
%n -- print Narrow if appropriate.
+ %t -- visited file is text or binary (if OS supports this distinction).
%z -- print mnemonics of buffer, terminal, and keyboard coding systems.
%Z -- like %z, but including the end-of-line format.
+ %e -- print error message about full memory.
%[ -- print one [ for each recursive editing level. %] similar.
%% -- print %. %- -- print infinitely many dashes.
Decimal digits after the % specify field width to which to pad. */);