If a CNAME RR is present at a node, no other data should be
present; this ensures that the data for a canonical name and its aliases
cannot be different. This rule also insures that a cached CNAME can be
used without checking with an authoritative server for other RR types.
Закупая сертификаты в больших объёмах, реселлер получает очень хорошие скидки.
https://vk.com/dev/standalone