The auto comment is added when one flags a question as a possible duplicate. These comments are generated in the form:
possible duplicate of [Question Title] (Link to the question)
With the recent implementation of [on hold], unclear etc. to close-votes (and flags; AFAIK users with low rep can still access the close-vote box); I think it's fair to auto-comment for the following cases as well:
- Questions asking for code must demonstrate a minimal understanding of the problem being solved. Include attempted solutions, why they didn't work, and the expected results.
- Please clarify your specific problem or add additional details to highlight exactly what you need.
- Questions concerning problems with code you've written must describe the specific problem and include valid code to reproduce it.
- Programming questions are off-topic on Meta Stack Overflow.
(The list is compiled from Stack Overflow and meta Stack Overflow; but can be extended for wider family of network sites)
A majority of questions don't get closed within let's say 5 minutes, and OP isn't notified of close votes received on their posts. The above reasons are pretty widely used and OP has no idea why the questions aren't getting enough attention unless they get down-voted (to eternity).
These auto-generated comments will, of course, be auto-deleted just like in the case of "possible dupes" once the question gets closed or the OP edits their question.