I don't see how the paragraph you quote is contradicting what I said. It is saying that the US dollar can be used as "legal tender" for certain things, but it doesn't define what it means precisely for something to be "legal tender". And that precise meaning was the point I was arguing.
Reference for the definition of legal tender by the UK royal mint:
https://www.royalmint.com/aboutus/policies-and-guidelines/le...?