Dictionaries
Pro
A dictionary is a list of choices you manage in one place and use in any number of choice fields. A bookshop might keep one Formats dictionary and use it on Books, on Writers and on a user's "preferred format" field. Add "Hardcover" to the dictionary once, and every field that uses it offers the new choice.
Each entry has a label, which editors see, and a value, which is what gets stored. You can reword labels at any time; stored values stay put.
VX also ships read-only system dictionaries for countries, currencies and units of measurement.
A short list you'll only use once, like $, $$, $$$, can stay as choices typed into the field. Once you'd type a list twice, make it a dictionary.