The Distributed Tracing Working Group has published Trace Context as a W3C Recommendation. This specification defines standard HTTP headers and a value format to propagate context information that enables distributed tracing scenarios. The specification standardizes how context information is sent and modified between services. Context information uniquely identifies individual requests in a distributed system and also defines a means to add and propagate provider-specific context information.
Original source: https://www.w3.org/blog/news/archives/8298