There should be a way to mark your answer as a comment, similar to how you can mark it as a community wiki post. This will make it easier to distinguish which answers are legitimate answers.
We are limited to how many characters we have in our comments. This leads to some posting comments as answers, which is approved as long as it's justified.
Although, there is no way to announce if your answer is a comment, other than informing readers that the answer is actually a comment (usually followed by a reason why you are not using the comment system). Some don't announce this, leading others to downvote and reply with "This should be a comment".
There are many reasons as to why you chose the answering system over the comment system:
- Your comment requires special formatting
- Your comment is too long
- You have less than 50 rep