A client &MUST-NOT; send a request containing Transfer-Encoding unless it
knows the server will handle HTTP/1.1 (or later) requests; such knowledge
might be in the form of specific user configuration or by remembering the
version of a prior received response.
A server &MUST-NOT; send a response containing Transfer-Encoding unless
the corresponding request indicates HTTP/1.1 (or later).
These "(or laters)" don't seem to be accurate.
These "(or laters)" don't seem to be accurate.