just realised never replied to this! Many thanks for your prompt reply! The paper was really useful.

Excellent. Did you get a sense of any cultural heritage value in brownfield sites or were they overwhelmingly seen as negative in those terms?

Indeed, and my personal favourite fossil fuel company sustainability reports.

That's true but the purpose is not to produce a good piece of work but to aid in decision-making. Reports can be disagreed with or ignored rather than redrafted. I bet you could point to some pretty ropey Palaeolithic gray lit evals which wouldnt have made it through your peer review??

Must admit - I assume gray lit essentially means lack of external peer review, which is a useful distinction. In planning, documents can easily be factually correct with a clear conscious or unconscious bias.