php-fpm comes with a manpage: /usr/local/man/cat8/php-fpm-5.3.0 This can be viewed with less /usr/local/man/cat8/php-fpm-5.3.0 but 'man php-fpm' or 'man php-fpm-5.3.0' doesn't reach it.
Why is that? My man.conf says
8 /usr/{share,X11R6,local}/man/{cat,man}8
