Original text:
response. Some of response codes that are defined in RFC1035 have acquired <del> their own shorthand names.  Some common response code names that appear without reference to the numeric value are "FORMERR", "SERVFAIL", and "NXDOMAIN" (the latter of which is also referred to as "Name Error").  All of the RCODEs are listed at </del>  http://www.iana.org/assignments/dns-parameters, although that site uses mixed-case capitalization, while most documents use all-caps.  "A pseudo RCODE which indicates that the name is valid for the given class, but there are no records of the given type.  A NODATA Empty non-terminals (ENT) F  Fast flux DNS Forward lookup Forwarder N NODATA  NSEC NSEC3  Naming system Negative caching Negative response Root zone S  SOA field names Secondary server Secure Entry Point (SEP)

Reviewer comments:
I have added your text (approximately) and merged the pull request.
During the discussion that led to RFC 7719, there was a request to split out error names in their own terms to make them easier to find in the document. Now with the index in place, this seems like a good idea.
Oooh, yes, I think that this would be great. [Sorry for the non-substantive / bikeshed comment]
Entered in the doc as URL
I think this is ok, but I'd like a tiny edit before the list starts: "The names as of this writing are described below, but the official list is in the IANA registry." Or something like this. I just don't want to suggest we're arguing with the authoritative registry.

Revised text:
response. Some of response codes that are defined in RFC1035 have acquired  <ins> their own shorthand names.  All of the RCODEs are listed at </ins> http://www.iana.org/assignments/dns-parameters, although that site uses mixed-case capitalization, while most documents use all-caps. <ins> Some of the names are described here, but the official list is in the IANA registry. "No error condition" (Quoted from RFC1035, Section 4.1.1.) "Format error - The name server was unable to interpret the query."  (Quoted from RFC1035, Section 4.1.1.) "Server failure - The name server was unable to process this query due to a problem with the name server."  (Quoted from RFC1035, Section 4.1.1.) "Name Error - Meaningful only for responses from an authoritative name server, this code signifies that the domain name referenced in the query does not exist."  (Quoted from RFC1035, Section 4.1.1.) "Not Implemented - The name server does not support the requested kind of query."  (Quoted from RFC1035, Section 4.1.1.) "Refused - The name server refuses to perform the specified operation for policy reasons.  For example, a name server may not wish to provide the information to the particular requester, or a name server may not wish to perform a particular operation (e.g., zone transfer) for particular data."  (Quoted from RFC1035, Section 4.1.1.) </ins> "A pseudo RCODE which indicates that the name is valid for the given class, but there are no records of the given type.  A NODATA Empty non-terminals (ENT) F <ins> FORMERR </ins> Fast flux DNS Forward lookup Forwarder N NODATA <ins> NOERROR NOTIMP </ins> NSEC NSEC3 <ins> NXDOMAIN </ins> Naming system Negative caching Negative response Root zone S <ins> SERVFAIL </ins> SOA field names Secondary server Secure Entry Point (SEP)