Editing HTTP (section)

=== Request syntax ===
A client sends ''request messages'' to the server, which consist of:<ref name="rfc9112-2.1">{{cite IETF |rfc=9112 |sectionname=Message format |section=2.1 |title=RFC 9112: HTTP/1.1}}</ref>

* a '''request line''', consisting of the case-sensitive request method, a [[Space (punctuation)|space]], the requested URI, another space, the protocol version, a [[carriage return]], and a [[line feed]], e.g.:
{{sxhl|2=http|1=GET /images/logo.png HTTP/1.1}}
* zero or more [[HTTP request header field|request header fields]] (at least 1 or more headers in case of HTTP/1.1), each consisting of the case-insensitive field name, a colon, optional leading [[Whitespace (computer science)|whitespace]], the field value, an optional trailing whitespace and ending with a carriage return and a line feed, e.g.:
 Host: www.example.com
 Accept-Language: en
* an empty line, consisting of a carriage return and a line feed;
* an optional [[HTTP message body|message body]].

In the HTTP/1.1 protocol, all header fields except <code>Host: hostname</code> are optional.

A request line containing only the path name is accepted by servers to maintain compatibility with HTTP clients before the HTTP/1.0 specification in {{IETF RFC|1945}}.<ref name="apacheweek_com-http11">{{cite web |title=Apache Week. HTTP/1.1 |url=https://www.apacheweek.com/features/http11 |access-date=2021-05-03 |archive-date=2021-06-02 |archive-url=https://web.archive.org/web/20210602213136/http://www.apacheweek.com/features/http11 |url-status=dead }} 090502 apacheweek.com</ref>