Writing Stack Exchange is a Q&A site for anybody interested in the
craft of professional writing, editing, and publishing. We cover a
wide variety of topics, including fiction, technical documentation,
scholarly articles, business writing, non-fiction, scripts, and blogs.
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professional writing. (ref)
I interpret this broadly. "Professional writing" can mean writing that is sold to a publisher for use as a book, article, or other work. It can also mean writing used in your profession. Letters, reports, manuals, etc. Or the art of learning to write to professional standards (anything done in school).
People who post here about writing, editing, or publishing without the immediate goal of making money are still asking about doing these things to a professional level. In other words, doing it well.
I've seen a lot of comments in my time here about how we don't have a lot of professional authors (though we have more than many think) and some folks even throw some shade at that. The reality is that, if we had a minimum standard of publication credits (or whatever measure one might devise), participation here would drop like a rock.
No matter our experience, we can all benefit from questions asked at different levels. We also have people skilled at one thing looking to break into another (a tech writer who wants to write novels, a novelist who wants to start a publishing company, writers who want to become editors or teachers, etc).
I feel comfortable with the range of questions. Yes, it would be nice to have more people who could answer some questions about professional norms and the details of publishing, etc. But questions that nurture emerging writers are also welcome.