Even their imperial unit isn't. I grew up with imperial measures where a pint was 20 fluid ounces, not 16, making the imperial pint about 20% larger than the American pint. In both systems there are eight pints to a gallon.
The imperial gallon is defined as 4.54609 litres, while the American gallon is defined as 3.785411784 litres (usually spelt liters).
The American "middle" name is only truly useful when you KNOW what it is, and when you can definitely follow that one person and not a name-alike.
When the only thing you find in official records is an initial, and there are several people with that same "first name" "middle initial" combination, you still have difficulty ascertaining if you have the correct person. It gets worse later in their life - for women - when any "middle" name seems to get dropped in official records and the maiden surname (or initial of it) gets used instead. So, Magdalen Audrey Jones might be Magdalen A Jones, then Magdalen A Humphrey, then Magdalen Jones Humphrey or Magdalen J Humphrey. Or John Alexander Peters is known in records as John A Peters and is frequently mixed up with John Andrew Peters, from the same town, who is also in records as John A Peters. It doesn't help when both of them marry a woman named Caroline A.
