In scriptwriting mode, Scrivener automatically adds character names to the auto-complete list as you write. While this is for the most part convenient, it can prove to be a pain if you decide to change a character’s name, or accidentally type something formatted as Character & Dialogue instead of, for example, Technical Directions, as it will still be added to the list and appear in the options list every time.
If this happens, and you’re like me and want to keep things neat, you might feel the need to prune your auto-correct list. To do this, from the Menubar select Project/Auto-complete List, then in the pop-up window simply edit the list and click Save.
Note: if using Scrivener 3, the list can be found via the Menubar and Project/Project Settings…