1. Introduction

   The DNS is designed to be extensible to support new services through
   the introduction of new resource record (RR) types.  In practice,
   deploying a new RR type currently requires changes to the name server
   software not only at the authoritative DNS server that is providing
   the new information and the client making use of it, but also at all
   slave servers for the zone containing it, and in some cases also at
   caching name servers and forwarders used by the client.

   Because the deployment of new server software is slow and expensive,
   the potential of the DNS in supporting new services has never been
   fully realized.  This memo proposes changes to name servers and to
   procedures for defining new RR types aimed at simplifying the future
   deployment of new RR types.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].