On 10/04/2013 08:34, Moore, Richard wrote:
James, you do realise that designating “cm” a symbol has nothing whatever to do with RDA? “Cm” is a unit symbol in the International System of Units. See here: http://www.bipm.org/en/si/si_brochure/chapter5/5-1.html
“Unit symbols are printed in roman (upright) type regardless of the type used in the surrounding text. They are printed in lower-case letters unless they are derived from a proper name, in which case the first letter is a capital letter […] Unit symbols are mathematical entities and not abbreviations. Therefore, they are not followed by a period except at the end of a sentence, and one must neither use the plural nor mix unit symbols and unit names within one expression, since names are not mathematical entities.”Clearly the presence or absence of a full stop doesn’t affect retrieval in a catalogue, but in describing “cm” as a symbol, and recording it as “cm”, RDA is simply following the international standard. If you have a gripe, it’s with the General Conference on Weights and Measures: http://www.bipm.org/en/convention/cgpm/
Yes, I do realize this. But I am a practical fellow and I follow the rule “If it looks like a duck, and walks like a duck, and quacks like a duck, it’s a duck.”
An abbreviation is a shortened form of a word, such as in. for inch or even lb. for pound. The period is there to bring out the fact that it is an abbreviation and not an typo. The use of periods varies from US to British. Therefore, in the US, you will tend to have Dr. Smith while in Britain you will have Dr Smith. http://en.wikipedia.org/wiki/Abbreviation#Periods_.28full_stops.29_and_spaces
A symbol is something different, such as % or $ or £, that is, a special sign that stands for a concept. You do not need a period in those cases. To me, it sure looks as if “cm.” is a shortened form of the word “centimeter(s)” whereas if they had chosen a special symbol such as ☺or ♠ or ║ that would be a different matter. The authorities never seemed to take the trouble to create symbols and chose instead to make a solemn pronouncement that their abbreviations are different from all other abbreviations in history, and therefore their abbreviations will henceforth be called “symbols”.
So, just because people in authority proclaim that “a duck is not a duck” does not mean that I–or anyone else–have to agree with them or believe them. I figure if they really wanted symbols for these things, they would have done some work and made some. But they never did.
As you mention, none of this makes any difference in searching or display and is therefore what I said is a “Gotcha!” (my own bit of terminology), that is: a piece of esoteric specialized knowledge that makes no difference to anyone, except to people I do not want to know. I used to be one of those people earlier in my career when I reveled in “Gotchas!”.
There have been far too many “Gotchas!” in cataloging rules and it would be a relief to eliminate as many as possible, leaving it all to the equally obscure “cataloger’s judgment” which actually means (I believe) “do what’s quick and easy and don’t worry about it”.