Edward C. Zimmermann wrote:

> I personally do not like x. I see nothing to gain from using x.

I summarized the arguments in my first mail. But arguments about 
notation always depend on cultural background. We could also use random 
characters or codes instead of '~', '?', '(', ')' etc. It's mostly about 
what you consider more convenient in which context.

> 1) MARC21  (the harmonized US and Canadian MAchine-Readable Cataloguing
> standard) uses u for uncertain or missing digits in its date fields. That
> format is the North American standard. It won't go away and its significance
> is not limited to North America. This means that many of us must already
> support u in this function.

So your context is MARC21, and in this context there is an argument for 
using the letter 'u' in this place. But everywhere outside the heavily 
outdated world of MARC, this practise is unknown and 'x' would be the 
more natural choice.

> 2) Worse still is the observation that x is also commonly used in the first
> position to represent hexadecimal codes.

I don't see this as a problem, as we don't support hexadecimal codes in 
the standard. Escape sequences do not use a single 'x' anyway, but some 
other escape character like backslash or ampersand, combined with 'x' or 
some other characters.

> What does 'x' deliver other than, at best, additional complication? Our
> formats are, after all, primarily for computers. In library systems characters
> such as '#', 'u' and '?' have been used. The character 'u' is not my
> favorite--- but understandable in MARC21 given the heavy use of punctuation
> characters for significant functions--- but clearly preferable to 'x'.
> In this context I think we might also want to consider the difference between
> unknown digits and a placeholder for a date (fill characters such as | in MARC).

Sorry, but arguing with special properties of MARC is like arguing with 
special properties of EBCDIC, troff, or any other standards from the 
1960s. I would even argue that having a special property in MARC, it is 
a good indicator that you do not want it in any serious current 
application. Or more drastically: MARC is a pest, that current Date/Time 
standards should not be infected with.


Jakob Vo▀ <[log in to unmask]>, skype: nichtich
Verbundzentrale des GBV (VZG) / Common Library Network
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