What exactly are you referring to here? There is some helpful info here, but I’m not sure it’s relevant:
https://www.inaturalist.org/pages/curator+guide#spam
I think duplicates are usually flagged.
https://forum.inaturalist.org/t/create-a-flag-category-for-duplicate-observations/29647
I also see curators flag much more frequently.
https://forum.inaturalist.org/t/add-10-new-hot-keys-to-the-identify-page/3122