Quoting myself, I know, but these old Imperial and other colloquial measurement systems cost society a lot of unnecessary time, energy, and expense. I know there's historical reasons for each, but it's really bothersome that we can't just leave them where they belong, as historical artifacts.Because gold is measured in Troy oz. and cotton in regular imperial ounces. But a pound troy is 12 T.oz., which is less than a regular imperial pound, being 16 imperial ounces.
Just using the above Troy ounce with gold as an example, I wonder how many people get scammed per year, paying Troy ounce pricing for gold items and receiving their weight in Imperial ounces, due to unscrupulous sellers. If you don't know to ask...
The only duplicate name convention that makes any sense to me is imperial tons versus metric Tonnes, which are intentionally spelled different for disambiguity, although pronounced the same. The imperial ton is 2000 lb., and the metric Tonne is 1000 kg ~ 2200 lb. The rest of these duplicate ounces, pounds, and gallons should be left as historical artifacts, and their use as a primary form of measurement for sale made illegal by our various departments of weights and measures.
Don't even get me started on stupid stuff like "face cords" or "bush cords".