Defining labels and open vocabulary values

[clenk]

It doesn't seem like a SEP is able to define the meanings of new values in open vocabularies, or labels for the already existing SDOs. This isn't a new STIX Object nor an extension to an existing one, which is what the current SEP scope covers. Trust groups will want to be on the same page about labels and custom open vocab values, and a SEP could help with that.