Oh, mea culpa. Honestly I just found the opening page and didn't notice it needed payment to get to the rest of it. I naively assumed that since Adobe had published it with ISO's permission, it was free in both places.
No worries! How did you find the "opensource.adobe.com" link? I can't hit it with google, even with aggressive searches like "site:opensource.adobe.com filetype:pdf". And I can't seem to navigate there from the main page.