To search for [words] in a man page:
apropos [words]
A shortcut for apropos:
man -k [words]
Use double quotes for exact phrases, with apropos and man alike:
apropos "an exact phrase"
No quotes for OR matching:
apropos any of these words
Very slow:
man -K [words]
Faster, as section [n] specified:
man [n] -K [words]
