neon is deliberately not compliant with section 23.4.2, and treats property names as a (namespace-URI, name) pair. This is generally considered to be correct behaviour by the WebDAV working group, and is likely to formally adopted in a future revision of the specification.

There is some confusion in this specification about the use of the “identity” transfer-coding. neon ignores the Transfer-Encoding response header if it contains only the (now deprecated) “identity” token, and will determine the response message length as if the header was not present. neon will give an error if a response includes a Transfer-Encoding header with a value other than “identity” or “chunked”.

neon parses and handles scoped IPv6 link-local literal addresses passed to ne_session_create since version 0.34, following the syntax in RFC 6874. An example host argument would be "[fe80::cafe%25eth0]" where "eth0" is the scope ID. Since RFC 9110 does not reference the extended syntax of scoped IPv6 literals, and a scope ID has no meaningful interpretation outside of the client host, it is omitted from the Host header sent over the wire. So the example argument here translates to an HTTP/1.1 header field of Host: [fe80::cafe].

neon is not strictly compliant with the quoting rules given in the grammar for the Authorization header. The grammar requires that the qop and algorithm parameters are not quoted, however one widely deployed server implementation (Microsoft® IIS 5) rejects the request if these parameters are not quoted. neon sends these parameters with quotes—this is not known to cause any problems with other server implementations.

RFC 7616 predates RFC 9112 and uses conflicting language around URIs. neon uses the RFC 9112 request-target in both the A2 grammar and the uri= parameter of the Authorization header. neon will accept (and resolve) any URI-reference in the domain= parameter for WWW-Authenticate response header field.

The neon XML parser interface will accept and parse without error some XML documents which are well-formed according to the XML specification but do not conform to the "Namespaces in XML" specification [REC-XML-names]. Specifically: the restrictions on the first character of the NCName rule are not all implemented; neon will allow any CombiningChar, Extender and some characters from the Digit class in this position.