It's the man page section number. I believe this dates back to when the man(uals) were actually printed out. You'd go to section 2 to find X to disambiguate f

It's the man page section number. I believe this dates back to when the man(uals) were actually printed out. You'd go to section 2 to find X to disambiguate from a different Y. http://www.december.com/unix/ref/mansec.html http://www.december.com/unix/ref/mansec.html