If I look at the man page for mutt it has this at the bottom.
curses(3), mailcap(5), maildir(5), mbox(5), mutt_dotlock(1), muttrc(
ncurses(3), sendmail(1), smail(1).
Mutt Home Page: http://www.mutt.org/
The Mutt manual
I wanted to look up ncurses, so I typed "man ncurses" but it said there was no man entry for it. So where am I supposed to find that reference? What is the (3) for?