In the original source material, there's a scene where Alice asks Bob how he got a noticable scar on his face. Bob then goes into a long, epic tale of a past exploit of his that ultimately resulted in him getting his scar.
Then in the film adaptation of said material, we get the same scene of Alice asking the big question. Only this time Bob, for whatever reason, decides not to exposit it's origin, leaving Alice, and the audience, in the dark.
Often times, due to time/money constraints, backstory and history from the source material has to be left out for practical reasons. Unlike an Adaptation-Induced Plot Hole, this doesn't necessarily hurt the narrative but does serve to create a Noodle Incident for anyone not familiar with the source material.
Often crosses over with Cryptic Background Reference.
Five hats means that five tropers think it is ready to publish.
You are saying that you think this draft is ready to be published. That means the description is not ambiguous,
it doesn't duplicate an existing trope, there are at least three examples, and the title makes sense.