As developer and SME, I don't answer open ended questions. If someone asks such a question I will ask a question in return to get to what is really needed by the asker. Not all SME's will do that.

That contrived example is actually a lot better than the crap requirements I usually have to work from....

Is setting a 15 minute meeting to chat about the requirements out of the question? That’s probably what I would do in this type of situation.

I think you'll get better SE answers with a real example as opposed to a contrived/falsified one. I understand the rationale (privacy?), but it makes it impossible to understand the context when I can't Google these acronyms to understand their relationships. Surely there's a way to protect privacy without making the example un-Google-able?

To short for a real answer but.... ask the Domain Expert in the same manner that you'd ask a question on StackOverflow. Keep it focused and demonstrate what you know.

"here are some proposed ways of solving it" - Too much choice. Give one proposal. They'll tell you what's wrong with it. Their change requests may fit another proposal you had in mind. They'd never told you to just do that, though in most cases (as to my experience).

"I don't understand requirement X, could you please explain what -whatever- means?". That is a really, really bad question. What do you not understand? Such a question would likely be bad received on SO, so its not surprising it gets bad answers from the experts. Ask them SO-like questions. Focused on what exactly you don#t understand, with the research you have done so the experts know precisely what to clarify and what gaps to fill.

You should also treat this kind of answer as a warning that you're trying to pin down some minor detail, and the SME thinks that you are missing some fundamental requirements and you may need to review the overall design.

There used to be a discipline called “systems analysis” ...

The Agile solution is to have a closer working relationship with the SMEs. Can you get them to come to your office and do their work there or can you work at their office?

This doesn't warrant a full blown answer but this might help you: Talk about the process. You must know the whole process. What comes in, what comes out, how it is displayed, how it interacts with other processes. Have a meeting, two hour long meeting, two day long meeting or more meetings until the whole process you are "IT-ing" is clear. You never ask domain experts open ended questions about design. Only about process. And write things down. You cannot design for process you do not understand or make algorithm for.

If they use a word you do not understand, ask them about it.

Communication is work. Sounds like you want them to do all the work. Don't we all...

To back up that last comment - a Subject Matter Expert is called that for a reason - they are not (typically) expected to be System's Analysts. If the info they give you is at the wrong level, it is because _ you _ have asked the question incorrectly. As technical folk, they are likely to appreciate short pithy questions far more than big open questions, unless they are really bored.

@JonP an answer is an answer regardless if it's short or long (Kilisi constantly demonstrates such fact as you can see on the answers below ;) )