Apple, Inc. Network Systems Research and Design Path Steering is a mechanism to discover paths to the producers of ICN content objects and steer subsequent Interest messages along a previously discovered path. It has various uses, including the operation of state-of-the-art multipath congestion control algorithms and for network measurement and management. This specification derives directly from the design published in _Path Switching in Content Centric and Named Data Networks_ (4th ACM Conference on Information-Centric Networking - ICN'17) and therefore does not recapitulate the design motivations, implementation details, or evaluation of the scheme. Some technical details are different however, and where there are differences, the design documented here is to be considered definitive. This document is a product of the IRTF Information-Centric Networking Research Group (ICNRG). It is not an IETF product and is not an Internet Standard.