Editing HTTP (section)

====HTTP/0.9 Deprecation====
In {{IETF RFC|7230}} Appendix-A, HTTP/0.9 was deprecated for servers supporting HTTP/1.1 version (and higher):<ref name="rfc7230-Appendix-A">{{cite IETF |rfc=7230 |sectionname=Appendix-A: HTTP Version History|appendix=A |title=RFC 7230, HTTP/1.1: Message Syntax and Routing|page=78}}</ref>{{Blockquote |text=Since HTTP/0.9 did not support header fields in a request, there is no mechanism for it to support name-based virtual hosts (selection of resource by inspection of the Host header field).  '''Any server that implements name-based virtual hosts ought to disable support for HTTP/0.9'''.  Most requests that appear to be HTTP/0.9 are, in fact, badly constructed HTTP/1.x requests caused by a client failing to properly encode the request-target.
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Since 2016 many product managers and developers of user agents (browsers, etc.) and web servers have begun planning to gradually deprecate and dismiss support for HTTP/0.9 protocol, mainly for the following reasons:<ref name="HTTP/0.9-chrome-deprecated">{{Cite web|url=https://groups.google.com/a/chromium.org/g/blink-dev/c/OdKnpLlvVUo/m/1EpFGVUjAwAJ|title=Intent to Deprecate and Remove: HTTP/0.9 Support|website=groups.google.com|date=2016-06-30|access-date=2021-10-15|language=en|author=Matt Menke}}</ref>
* it is so simple that an RFC document was never written (there is only the original document);<ref name="HTTP/0.9-specifications"/>
* it has no HTTP headers and lacks many other features that nowadays are required for minimal security reasons;
* it has not been widespread since 1999..2000 (because of HTTP/1.0 and HTTP/1.1) and is commonly used only by some very old network hardware, i.e. [[Router (computing)|routers]], etc.
{{refn|group=note|In 2022, HTTP/0.9 support has not been officially completely deprecated and is still present in many web servers and browsers (for server responses only), even if usually disabled. It is unclear how long it will take to decommission HTTP/0.9.}}