Cisco Systems, Inc. Ericsson Cisco Systems, Inc. Nokia This document specifies a new YANG module update procedure that can document when non-backwards-compatible changes have occurred during the evolution of a YANG module. It extends the YANG import statement with an earliest revision filter to better represent inter-module dependencies. It provides guidelines for managing the lifecycle of YANG modules and individual schema nodes. It provides a mechanism, via the revision-label YANG extension, to specify a revision identifier for YANG modules and submodules. This document updates RFC 7950, RFC 6020, RFC 8407 and RFC 8525.