f this
specification, because passing attribute using JSON, XML, or Protocol Buffers
does not change the semantics of the attribute. Different implementations
can choose different representations based on their needs.</p><h3 id=http-mapping>HTTP Mapping</h3><p>Because many systems already have REST APIs, it makes sense to define a
standard HTTP mapping for Istio attributes that are compatible with typical
REST APIs. The design is to map one attribute to one HTTP header, the
attribute name and value becomes 