The ONOS Project focuses on the development and support of the Open Network Operating System (ONOS) and its feature proposals and use cases. To elaborate:
This guide focuses on ONOS itself. Use cases have development cycles and contribution procedures independent of the ONOS project. While the procedures and tools used by a use case often overlap with those used for ONOS (and discussed here), those who are interested in working on a use case should refer to the information provided by their use case of interest for specifics.