CPHL, or the Cross-Platform Hypertext Language is a hypertext specification for RESTful APIs. CPHL is based on HAL, but is designed to allow for greater flexibility, transmission of additional information, and empowerment of resource specific code on demand.
For example: application/cphl+json will return the _definition and _links collections, but omit the "code" property for the different _links actions as well as the content-types available under "formats."
application/cphl+json+code will return the _definition and _links collections, but omit the formats property.
application/cphl+json+code+formats will include both the code and formats properties.
application/cphl+json+formats will include the formats property, but continue to exclude the code properties.