As a student using Scrivener for academic purposes- I would love to be able to ‘tag’ (that is - apply a keyword) to just a highlighted section of text. This is because in my literature review - I might have a long document and I want to apply keywords just to certain relevant sections of that document (and I don’t really want to split it into too many tiny bits so that i can keyword just bits).
This is for “gathering of ideas” - if I’ve got 50 authored papers - I want to search just for each bit I’ve tagged as, for example, “quote this paragraph”.
People have discussed this at length, and the response has been that the Keywords function shall remain as a document-level metadata feature. However, you could create inspector comments based on a selection, and input some kind of code (something that isn’t likely to be in the text itself, like “mythReference” or “key-myths” if you were tagging passages related to myths). Then you could search for those multi-word phrases to find them again. With the inspector comments visible, you can click on them to scroll to the appropriate passage in any of the documents loaded into the editor.
But you may find that splitting the documents around each passage & using the Keywords feature is the more useful approach; using the search field in the toolbar will net you just the passages that way, instead of the entire document.