Copyright might restrict reposting parts, but nothing (except perhaps license agreements) restricts public discussion.
You can see this by the fact that Wikipedia has complete details of the ISO date standard (as referenced in the parent tweet Tim replied to).
And nobody's doing that.
Most people aren't going to quote much anyway, which means the people who don't know what's referenced can't understand it because they have no context. Which brings us back to square one, you can't meaningfully discuss the content in public.
Fair Use exception in the US, and I think that would be covered by Fair Dealing in the UK and similar countries.
You absolutely can, trivially as the huge number of discussions or the ISO date format on StackOverflow show: https://stackoverflow.com/search?q=ISO+Date
There are lots of issues with locked down standards. But copyright means they can't be publicly discussed is factually incorrect.
(Also fair use means it's fine to quote enough context for a meaningful discussion anyway)
You can discuss the general requirements, and paragraph numbers, etc, but there's a limit to how much somebody who has the document can quote without legal problems. Somebody else who sees the discussion can not know if the discussions contain complete enough information to "reverse engineer" the standard well enough to meet its requirements.
All those discussions about the ISO date standard involves getting information from somebody who has access to the document and who then shared the information in public. Not all documents has that degree of public commentary.
And if you need to ask about sections which haven't been previously described in sufficient detail for your needs, then you're personally relying on individual people who have access to read it and rewrite the information for you. Which is a lot of work and also legally uncertain.
Fair use standards are not all that consistent. And that's a legal defense you can use in court after already having been sued, not before. Enough for context can vary between one sentence or three pages.
That's where expensive consultants who already have interpreted the standards are paid to explain to you. It's a bit of a "cartel" imho.