— Confusingly named it 'Business Communication Standards'
— Published the web version in a barely readable way
— Hid the PDF behind the paywall
Honestly, I've got no idea why one would publish a standard under Creative Commons license in such a strange way. Nevertheless, I've found it.
I believe the guide itself is useful. So with some Python and a lot of manual work I turned it into a GitHub-hosted markdown book, EPUB and PDF. Give it a try ツ