The FAQ says at the very top:
... related to managing computer systems in a professional capacity.
What does that 'professional capacity' mean? I get paid to do what I do, so isn't everything I do relating to that capacity topical?
First of all "professional" is more than just a job-description with a paycheck, it's a mindset. But more on that later.
Over the years the ServerFault community has evolved a rough consensus definition of what that phrase means. There are two broad categories we assess new questions against regarding 'professional capacity'.
The first is more concrete and overlaps with a few other items in the FAQ under NOT About. The second is much more complex.
This is more of an exclusionary line. Questions that fail this test are also likely one or more of:
We've found that scoping "professional capacity" to just production systems does a great job of keeping questions definitely topical.
Of these the development systems item gets us the most pushback. There are very good reasons we eliminate these systems from consideration:
However, some questions related to systems which are not nominally production may be on topic, particularly if they meet certain criteria:
A question about a non-production system which does not meet at least those three constraints will certainly be off topic.
Is a professional
Good questions are ones that demonstrate that the asker has the mindset of a professional sysadmin. A question that passes this test demonstrates several of the following qualities:
Hypothetical what-if questions frequently fail this test, but some don't.
The more I see questions being closed as off topic because the member who asks seems a bit lost or not at ease with the system being used, I would say that professional capacity on SF seems to refer as being a guru or a demi-god.
We seem to forget that it's impossible to know every single technology or field in IT.
We also seem to forget that people need to start somewhere. Is a system administrator with 6 months experience less of a professional?
If so, then SE would need to add new site for near-professionals.
Is it possible that a network administrator who does magic with switches and routers might not be familiar with the inner working of Microsoft Active Directory or Syslog-ng? ...absolutely.
Is it possible that a Linux administrator who codes useful bash script in no time might not be familiar with Cisco IOS or Oracle DB? ...absolutely.
The problem is, in both situations, the user might want to ask question outside of their professional knowledge.
If they do, then starts the "this-does-not-belong-here" dance. All based on the wrongful assumption that the person is not a pro.
I'd like to add my opinion that while the Help section's bullet points on What topics can I ask about here? doesn't come right out and exclude academic research or student projects, the term Professional Capacity should NOT include these. Students coming to ServerFault discussing a project they are working on for school and needing assistance should be considered Off-Topic.
There are gray areas, as always (student intern being paid to work on a corporate project), but by and large student questions should be considered off-topic as they don't fall under professional capacity.