Online reference manual (man) pages provide immediate documentation about a command, function, subroutine, and so on.
You can display the man page for the C compiler by running the command:
example% man cc
Throughout the C documentation, man page references appear with the topic name and man section number: cc(1) is accessed with man cc. Other sections, denoted by ieee_flags(3M), for example, are accessed using the -s option on the man command:
example% man -s 3M ieee_flags