It seems that by default, SELinux policy manpage is not available. Here’s how to make it available.

  1. First install selinux-policy-devel package
  2. Then generate the man page by running:
    # sepolicy manpage -a -p /usr/share/man/man8<br/>
    -a  : all domains
    -p : path to store the manpage (by default it’s /tmp)
    /usr/share/man/man8 – section 8 of manpage is for system admin command

  3. Create or update manual page index caches
    # mandb

  4. Benefit
    # man -k _selinux (or e.g. ”man httpd_selinux“)

Ref: https://www.certdepot.net/rhel7-deploy-selinux-man-pages/