xkcd #3138: Dimensional Lumber Tape Measure
Title text:
A person with two watches is never sure what time it is, especially if I got them one of the watches.
Transcript:
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Source: https://xkcd.com/3138/
An Inch meant something different for most countries not too long ago. If the Chinese inch is a knockoff, then so is the US inch. Only the UK inch is the one truly inch!