Deciding on "expert" seems completely intractable. What if one fellow has spent a decade studying the subject and agrees with 90% of his fellow decade-studiers on 90% of things but the remaining 10% of topics he has views shared by approximately no one. Is he a crank or an expert? What if he's fairly persuasive to layman/politicians and thus is the head of the Bank of England?

Additionally, if a subject matter does not lend itself to experimentation or feedback mechanisms then you can easily have all the experts be consistently wrong for decades due to group think or conformal pressures.

In this case I think the fellow should be allowed to speak on the topic he studied.

I agree generally in the end you'd have to trust the forum admins to publish some rules and follow them, but that's already the case in any forum. I'm sure some people would like it and some would hate it. It's at least an interesting alternative to the majority of people not knowing what they are talking about but confidently posting as if they do, even if it's just one of the kinds of forums in the mix in the world.

Not to mention that people are often legitimate experts in a field and a leading expert on their own theory, and yet spout palpable nonsense about what supporters of the alternative theory believe to boost the credentials of their own theory.

Heterodox monetary theories are a particularly good example of this...

You can't frame rules to capture something like "expertise" which has an infinite scope. I don't know how to express it, but it feels wrong. If you could frame such rules then the subject under consideration might be so trivial, making the whole exercise of tagging pointless.

Or maybe you mean you want people to be able to share credentials like a degree and claim expertise without us having to do the extra work of judging the quality of those qualifications?

I'm not actually going to make the forum so don't have a detailed plan.

> It would be interesting if somehow credible (including heterodox) experts could be tagged so you could differentiate them from people with no or limited knowledge larping as experts.

These endorsements are highly sought by the larpers and confidently incorrect. Meanwhile the actual experts aren’t as interested in going through the process of getting the mark.

One pattern I’ve seen repeated across many forums over decades of internet use: The confidently incorrect have more time and energy to dedicate to online misinformation than the actual experts. I’ve watched many knowledgeable forum users eventually tire of participation and leave communities because they get overrun by younger, inexperienced people who are still in the phase of life where we think we know everything.