Wanted. A new definition for Grey (or is it Gray?) Literature - can you help?

"So, not least because of Shirky's button and today's full-featured self-publishing platforms, I think a new definition of grey literature is needed. I propose it could be simply: any output that belongs in the scholarly record which wasn’t made public via a system of publication, distribution and bibliographic control compatible with standard scholarly workflow and library systems, such as a book, journal, pre-print service or repository.