List of HTTP header fields
HTTP header fields ( often inaccurate HTTP headers ) are components of the Hyper Text Transfer Protocol (HTTP ) protocol header and transmit important for the transfer of files via HTTP parameters and arguments, such as language or character set, and often information about the client. Often " HTTP header " used interchangeably, but has the ambiguity between a single field of the header block and the entire header block. Here, for all of the header fields, the term "header", and used for a single row in the header, the term " header field " according to RFC 2616.
The individual fields in the header are always after the request (Request ) line transmitted ( for example, GET / index.html HTTP/1.1 ) or the response ( Response) line ( if successful HTTP/1.1 200 OK).
The lines of the header itself are key - value pairs, separated by colons (eg Content-type: text / html).
The names are specified fixed by different standards.
The line endings are marked by the combination of characters CR LF (carriage return, line feed), the end of the header is signaled by a blank line, which is similar to the transmission of
Most header fields are standardized by the IETF RFCs, such as the "core" in RFC 2616 and RFC extensions in 4229th The standards laid down in these specifications must be present in all HTTP implementations. In addition, manufacturer or projects additional extensions can build into their software ( for then, however, there is no guarantee that they will be " understood" by all implementations correctly ). Depending on the product can define your own header fields and the individual user or administrator.
Viewing can be the permanent and temporary header fields at the IANA.
Request - header fields
The request fields occur on a web server in the header of the request an HTTP client (eg browser). They include, for example, information about the requested file and the file types accepted by the client.
For exact investigation was the reading of RFC 2616, Chapter 14 (pp. 62ff, PDF, 551 kB) recommended ( chapter number in the second column of the table).
Response header fields
1 ) Not in official HTTP/1.1-Standard because (Section 15.5), a number of safety concerns were raised. Content-disposition is described in detail in RFC 2183.
General, non-standard fields
Request fields
Non - standard header often carry a ' X ' at the beginning. With RFC 6648 applies the prefix X - deprecated.