If one is to be really fussy, "The International System of Units" (see link in original posting) does not talk of "SI symbols", only of "SI units". The uses the term "symbols" in conjunction with "SI Base Units", "SI Derived Units", "Units used with the SI" and indeed with every other classification of unit.
For those of us who live in Europe, the EU directive 80/181/EEC (which catalogues units of measure that may be used within the EU) uses the word "symbol" in the same way as is done in SI, but extends it to include those units of measure that may temporarily be used in the United Kingdom in addition to those used elsewhere in Europe. In particular the symbols "in", "ft", "yd" and "mile" are defined in the directove for use on road signs, but our Department for Transport has chosen to ignore the directive and use its own symbols - double apostrophe, double apostrophe, "yd" and "mile" or "m". ----- Original Message ----- From: "Anon Anon" <[EMAIL PROTECTED]> To: "U.S. Metric Association" <[email protected]> Sent: Wednesday, December 07, 2005 11:07 AM Subject: [USMA:35344] RE: Numerical codes for measuring units? > James R. Frysinger wrote: > >Purely out of fussiness, the SI symbol for > >unified atomic mass is u, not amu. > > > Also out of fussiness: > It does not have an *SI* symbol. It is not an SI unit. > http://www.bipm.org/en/si/si_brochure/chapter4/table7.html > > > Terry
