List of acceptable human languages for response. Media type(s) that is/are acceptable for the response. Request fields Standard request fields NameĪcceptable instance-manipulations for the request.
For example, the Apache 2.3 server by default limits the size of each field to 8,190 bytes, and there can be at most 100 header fields in a single request.
However, most servers, clients, and proxy software impose some limits for practical and security reasons. The standard imposes no limits to the size of each header field name or value, or to the number of fields. For example, a browser may indicate that it accepts information in German or English, with German as preferred by setting the q value for de higher than that of en, as follows:Īccept-Language: de q=1.0, en q=0.5 Size limits Many field values may contain a quality ( q) key-value pair separated by equals sign, specifying a weight to use in content negotiation. in User-Agent, Server, Via fields), which can be ignored by software. Field values Ī few fields can contain comments (i.e. An earlier restriction on use of Downgraded- was lifted in March 2013. Non-standard header fields were conventionally marked by prefixing the field name with X- but this convention was deprecated in June 2012 because of the inconveniences it caused when non-standard fields became standard. HTTP/2 makes some restrictions on specific header fields (see below). This is in contrast to HTTP method names (GET, POST, etc.), which are case-sensitive. Additional field names and permissible values may be defined by each application. The permanent registry of header fields and repository of provisional registrations are maintained by the IANA. Field names Ī core set of fields is standardized by the Internet Engineering Task Force (IETF) in RFCs 7230, 7231, 7232, 7233, 7234, and 7235. In the past, long lines could be folded into multiple lines continuation lines are indicated by the presence of a space (SP) or horizontal tab (HT) as the first character on the next line. The end of the header section is indicated by an empty field line, resulting in the transmission of two consecutive CR-LF pairs. Header fields are colon-separated key-value pairs in clear-text string format, terminated by a carriage return (CR) and line feed (LF) character sequence. The header fields are transmitted after the request line (in case of a request HTTP message) or the response line (in case of a response HTTP message), which is the first line of a message.
0 kommentar(er)
