XContentType

XContentType is a non-standard HTTP header that was intended to specify the media type of the content in an HTTP message. While it was not formally standardized by the IETF, it gained some traction and was implemented by various web servers and clients. Its purpose was to provide an alternative or supplement to the standard Content-Type header.

The XContentType header aimed to offer a way to explicitly declare the type of data being transmitted, such as "application/json" or "text/html". This could be useful in scenarios where the standard Content-Type header might be absent, ambiguous, or overridden. For instance, some systems might use XContentType to ensure a specific interpretation of content, even if the primary Content-Type header suggested something else.

However, due to its non-standard nature, the use of XContentType was inconsistent. Browsers and servers did not universally support it, leading to potential interoperability issues. The IETF ultimately did not ratify XContentType as a standard HTTP header. The standard Content-Type header is the widely accepted and supported method for indicating the media type of an HTTP message body. Developers are generally advised to use the standard Content-Type header for reliable and cross-platform compatibility.