UNOFFICIAL_CODE_REGISTRY

http_status_codes2::status_code_registry

Constant UNOFFICIAL_CODE_REGISTRY 

Source 
pub const UNOFFICIAL_CODE_REGISTRY: [(usize, &str, &str, &str); 4];
Expand description

Representation of an unofficial HTTP status code registry. Includes a few proposed or popular unofficial HTTP status codes.

Tuple values represent the status code, description, references, links to references.

Thanks go to Evert Pot and his Series of posts on HTTP status codes.