Doesn't work. Too many people don't read the instructions, or do but don't follow them, not matter how much big, red, bold, flashing text tricks you use.
The only reliable way around it we've found with our clients is to be dickish with SLAs: insufficient information means the SLA clock stops dead. No error code/message details, no SLA, and I can & do take my merry time (if I ever get around to looking at that ticket instead of the many that do have sufficient information).
Though it helps that our large clients always knock down support costs by refusing to pay for first-line support because "our internal helpdesk can do that" so they should be performing at least minimal triage. It might not wash in other environments.
The really irritating part is when they seem to do their level best to avoid giving any specific details:
Them: some users are having a problem with a form
Us: which users? Could you name at least some, and if any don't have the problem name at least one of them. And which form? And do they get a specific error?
Them: Actually it is quite a few users.
Us: which users? Could you name at least some, and if any don't have the problem name at least one of them. And which form? And do they get a specific error? Is the problem loading information or saving it? IF the latter does any of the data save despite the error?
Them: More users are now reporting the error.
Us: which users? Could you name at least some, and if any don't have the problem name at least one of them. And which form? And do they get a specific error? Is the problem loading information or saving it? IF the latter does any of the data save despite the error?
Lather, rince, repeat, until I state something like "we've tried with several user types and several forms in our test services, and can't reproduce the problem, unless you can produce the details requested we'll have to close the ticket as "can not reproduce", at which point they get shirty about us not being helpful but do provide the information requested.
Yes, I can often work out exactly what is going on from various exception logs, and sometimes to just to get the buggers off my back so I can get on with something more useful and interesting, but I resent having to dig for details that it would take almost no effort for them to provide either up front or after my initial request for clarification. IT isn't just "lay users" either, it is often people who really really should know better. IF you find yourself on the other side of this equation: give all the detail you can FFS, help us help you (countpoint: only give us facts, don't guess or otherwise make shit up).