The draft entitled Network Slice Provision Models was issues in February 2019 and will expire in August of that year. Alex Galis (UCL) and Luis Contreras (TID) have contributed to that document available at https://tools.ietf.org/html/draft-homma-slice-provision-models-00#page-15.
The issue addressed is the definitions and scopes of network slicing that vary to some degree from one organization to another. This document provides classification of provisioning models of network slice for clarifying the differences on the definitions and scopes.