We already have an agreed policy on closing duplicate story-id questions, that we only close them as duplicates where there's agreement from both parties that their questions are asking about the same property. It doesn't matter how "obvious" you think they are, if they aren't accepted, we don't dupe them off.
Closing Story-Ident questions as duplicates (where there's no acceptance)
As far as new questions are concerned, you have two choices;
- You can post a comment to the OP that you think their question is a dupe, preferably with a link to the suspected duplicate
"I think this is x, as detailed in the question here".
If the OP agrees, you can then mark it as a duplicate. This is the preferred option if the new question doesn't really add any extra details to the already answered question, or is a dupe of a dupe of a dupe.
- If you feel the need, you can post a new answer.
This is the preferable option where the other question doesn't already have an accepted answer or where the question adds significant detail (such as asking about a single story in an anthology).