https://wiki.freebsd.org/pkgng#Resources refers to http://people.freebsd.org/~bapt/pres-pkgng-bsdcan.pdf That's not found. Instead, https://people.freebsd.org/~bapt/pres/pres-pkgng-bsdcan.pdf http://freebsd-pkg.freebsd.narkive.com/K5W8YS0b/pdf-link-broken observed the problem a few months ago.