I recently asked a question about a well known short story, "The Mezzotint". I tagged it with the author name and the name of the book in which it was first published, Ghost Stories of an Antiquary. I note now that we also have a short-stories tag, which I didn't realise.
Anyway, it made me wonder how best to tag stand-alone stories that have gained traction under their own names. A lot of people would recognise the title of "The Mezzotint". Very few, though, would recognise Ghost Stories of an Antiquary. Not least because it's been republished in many, many other collections since then.
So how should we tag these stories? Using the story title and not the collection might be appropriate for "The Mezzotint", but it would be a poor fit for more modern collections which tend to stand together and don't gain fame as individual tales. But then, there is the chance they could appear in multiple collections. And since there is AFAIK a 5-tag limit if we throw in the author and short-stories too, we're going to run out of space.