How can I get a listing of what the canonical units are for the new built-in units system? They're definitely different than the units in the obsolete Units package. For example, Foot is a unit for length in the Units package. KnownUnitQ["Foot"], returns false, but KnownUnitQ["Feet"] returns true. It's not much of an issue when connected to the internet because Mathematica will automatically interpret the units, but if you're not connected and enter a non-canonical unit, you'll get an error, which is an annoyance. I can look up individual or groups of canonical units using {#, QuantityUnit[Quantity[1, #]]} & /@ {"m", "ft", "PSI", "BTU", "BTU/Hours/ft^2/Rankine", "InWC", "lbmol"} // TableForm, but again, that requires internet access. I suppose that I could just build up a list of the units that I normally deal with ahead of time using this method, but that won't be comprehensive and I'm sure it will lead to frustration later.

Thanks