debian=https://www.debian.org[Debian]
debian_nonfree_archive_area=https://www.debian.org/doc/debian-policy/ch-archive#the-non-free-archive-area[Debian's non-free archive area]
tts=http://www.template-toolkit.org[Template Toolkit]
-smtp_rfc=https://tools.ietf.org/html/rfc5321[RFC 5321]
+rfc_5321=https://tools.ietf.org/html/rfc5321[RFC 5321]
rfc_5322=https://tools.ietf.org/html/rfc5322[RFC 5322]
dkim_rfc=https://tools.ietf.org/html/rfc6376[RFC 6376]
dmarc_rfc=https://tools.ietf.org/html/rfc7489[RFC 7489]