Comments are allowed to be informal and there are few limitations on them and are frequently useful when an answer is not an appropriate form of writing, see What does a good answer on Quora look like?
A question comment can:
- Request clarification about the meaning of the question.
- Offer a personal thought about the question.
- Suggest how to make the question better.
- Ask about the topics on the question or make a suggestion about the topics.
- Suggest other question pages that may be relevant.
- Leave tips for how other users might research an answer to the question.
An answer comment can:
- Thank or praise the answerer.
- Ask for clarification about an element (or all) of the answer.
- Disagree with and/or debate the answer.
- Suggest ways to improve the answer.
Comments should not be:
- Mean, insulting, or confrontational.
- Answers to the question. If a comment would be appropriate as an answer to the question, then it should be an answer, not a comment.
Question Comments can be added using the link underneath question text that says "Comments." Answer Comments can be added using the link underneath any existing answer that says "Comments."
Comment threads & how to disagree in comments
In general, comment threads on Quora are interactions among strangers. Given that another person on the site may be new to Quora and/or doesn't know you, we require a higher level of politeness than other interactive platforms where users know one another and/or where more adversarial social norms are established and tolerated. A key goal of the Be Nice, Be Respectful policy is ensure that comments do not discourage or intimidate other people on Quora.
Disagreement and debate on Quora is encouraged and is often important to making the page more helpful. It is OK to disagree as long as your comments are civil, respectful, and polite, and as long as you give the impression of assuming good will on the part of the person you are disagreeing with. A good way of framing this test is: "If I am new to Quora and / or don't know you, would it be reasonable for me to perceive your comment as hostile or disrespectful toward me or what I've written?" The answer should be no.
In multi-comment threads where there is significant disagreement among people, a person should stop commenting on the thread before creating the reasonable impression that they are harassing, attacking, and/or bullying another person.