Safe or out (seefu / auto)
Overview
Safe or out (seefu / auto, from the English words) is a standard for judging whether an action or remark is within acceptable limits. The expression comes from calls in baseball, and in everyday conversation it's used like "That's safe (it's fine)" or "That's out (not okay)."
In a question box, you may judge whether the content of a question or the wording of an answer is "safe or out." The standard for this judgment differs from person to person and can change with culture and generation. It's precisely because a clear line is hard to draw that it's important to have your own standard.
Where the safe-or-out line falls in a question box
Things that are clearly out in a question box: questions that could lead to identifying someone's personal information, sexual harassment, abuse, and hints of crime. These are usually easy to judge as out.
The gray zone: questions about romance, appearance, family situations, and grades. These can be either safe or out depending on how the question is asked and how the person answering takes it. "What's your type?" is safe, but "You like X, don't you?" leans toward out. Even on the same topic of romance, the impression changes with how you ask.
Having your own standard
It's fine for the person answering to decide their own standard for safe and out. For example: "Love talk is okay," "No politics," "Dirty jokes get skipped." Deciding your standard in advance helps you hesitate less over questions.
Whether you make your standard public is also up to you. Writing "Off-limits questions: X" in your profile is one way to let senders know in advance. However, listing too many off-limits topics may raise the bar for sending a question. Show only the bare minimum of what's out, and handle the rest flexibly.