HTTP - Parameters

HTTP Version
HTTP uses a <major>.<minor> numbering scheme to indicate versions of the protocol.
HTTP/1.0

Uniform Resource Identifiers (URI) 
Is simply formatted, case-insensitive string containing name, location etc to identify a resource, for example a website, a web service etc.

Date/Time Formats
All HTTP date/time stamps MUST be represented in Greenwich Mean Time (GMT), without exception. HTTP applications are allowed to use any of the following three representations of date/time stamps:
Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123

Character Sets
You use character set to specify the character sets that the client prefers. Multiple character sets can be listed separated by commas. If a value is not specified, the default is US-ASCII.

Content Encodings
A content ecoding values indicate an encoding algorithm has been used to encode the content before passing it over the network. Content codings are primarily used to allow a document to be compressed or otherwise usefully transformed without losing the identity.
Like gzip.

Media Types
HTTP uses Internet Media Types in the Content-Type and Accept header fields in order to provide open and extensible data typing and type negotiation. All the Media-type values are registered with the Internet Assigned Number Authority ((IANA). Following is a general syntax to specify media type:
Accept: image/gif

Language Tags
HTTP uses language tags within the Accept-Language and Content-Language fields. A language tag is composed of 1 or more parts: A primary language tag and a possibly empty series of subtags:
en, en-US, en-cockney, i-cherokee, x-pig-latin