Minimizing ANY-Query Responses at Recursive Resolvers

The "ANY" query in DNS is a meta-query intended to match multiple resource record types associated with a given domain name, and can elicit responses that are significantly larger than those generated by single-type queries. While RFC 8482 defines a mechanism for authoritative servers to minimize ANY responses, a recursive resolver may still generate an ANY query response directly from its cache, thereby bypassing the authoritative side's ANY query minimization strategy. This document provides supplementary guidance for recursive resolvers on processing ANY queries to mitigate potential operational and security issues.