Content Types

Within the HTTP protocol the content type is a header field returned by the Web server as part of the response. This value is used to indicate the Internet media type of the information being returned. The content type is used by the browser to determine what mechanism to use to display the data returned from the Web server.

A content type is comprised of a type and subtype represented as type/subtype. Where subtype further describes the type parameter. For example image/bmp is an image type with a subtype of bmp (representing bitmap). This would indicate an image with the data stored as a bitmap.

The Web Server/400 product uses file extensions to determine what content type is associated with a particular file. This is configured within the content type configuration file.

Internet media type is a term which was originally derived from the Multipurpose Internet Mail Extensions (MIME)types. RFC 1521 and 1522 discuss and define the MIME types definition.

There are two different categories of content types:

officially registered
The registration process is defined within the Request for Comments (RFC) numbered 1590. The registration authority is the Internet Assigned Numbers Authority (IANA). RFC 1521 and 1522 also have information regarding the registration of MIME types.
non-registered
The non-registered content types are content types which have not been officially registered with the IANA. These content types have a type which begins with the "x-" characters. If you which to add any unregistered types to the content type configuration file they should also begin with the "x-" characters