Any man page references with underscores are broken. The link only applies to the last part of the name. e.g. xo_create(3) only "create" is highlighted, and it links to non-existent man page create(3) https://man.freebsd.org/cgi/man.cgi?query=create&sektion=3&apropos=0&manpath=FreeBSD+13.2-RELEASE+and+Ports It's really obvious in the "see also" section, where there are many broken references. https://man.freebsd.org/cgi/man.cgi?query=libxo&sektion=3&apropos=0&manpath=FreeBSD+13.2-RELEASE+and+Ports