[uf-discuss] Currency Quickpoll: Preliminary results

Lachlan Hunt lachlan.hunt at lachy.id.au
Fri Oct 13 01:19:03 PDT 2006

Mike Schinkel wrote:
> Thanks for the clarification.
> Further questions (and forgive me if I missed any of this before I joined):
>>> Currency symbol identification
> This is a naïve question: Doesn't the ISO 4217 code *imply* a symbol?  It
> appears so here: http://www.xe.com/symbols.htm  Doesn't including this in
> the microformat create redundancy?

It's not just about identifying which symbol represents the currency, 
but also which currency that symbol represents.

> Alternately, can't the symbols be extracted as not being alphanumeric
> characters?

For a program to do so, it would have to be aware of every single 
alphanumeric character in Unicode.  That does not just include 
[A-Za-z0-9].  It might be easier to do the reverse and know of every 
character that isn't a known currency symbol, but then even that list of 
symbols is missing some.

* U+FE69 ﹩ (Small Dollar Sign)
* U+FF04 $ (Fullwidth Dollar Sign)
* U+FFE5 ¥ (Fullwidth Yen Sign)
* etc.

It's much easier for the author to explicitly state which character(s) 
represent the symbol, than implementing heuristics to guess.

> Broader Question: 
> Isn't the idea behind Microformats to be as consise, cohesive, and single
> purposed as possible?  If so, wouldn't that argue for "combination with
> units (ex. $34 per gallon, $2 per miles)" being out of scope and begging the
> need for a microformat that allows unit designation, i.e. hUnits?

Yes.  Tackling the problem of identifying specific units under the 
currency format is far too complicated when you consider the sheer 
number of units there are, including SI units, Imperial units and US 
customary units, used for various quantities including number of units, 
length, mass, time, volume, area, energy, etc.

However, the format could make provisions for some form of quantity, 
even if it doesn't explicitly define what such quantities are.

e.g. price per Litre:

<span class="money">
   <abbr class="currency unit" title="AUD">$</abbr>1.23
   <span class="quantity">L</span>

Or for each unit:

<span class="money">
   <abbr class="unit">$</abbr>4.95
   <span class="quantity">each</span>

That way, if and when a microformat for units of measurement is 
introduced, that could easily be expanded to the following.  e.g.

   <span class="quantity si-unit">L</span>

> My last thought on the subject, is why are we using full names for currency
> and amount instead of "cur" and "amt" to minimize bloat when hCard uses
> names like "fn?"

One of the problems I have with hCard is that those abbreviated class 
names are difficult to comprehend and remember.  e.g. It's easy to get 
confused about what 'fn' means, since it could easily stand for family 
name, though it doesn't.  (I'm not exactly sure what it stands for, 
though I assume it means "formatted name" even though it's not 
explicitly stated as such in the vCard RFC)

Abbreviations can be good in many cases, but you have to be careful not 
to introduce too much confusion or ambiguity for authors.

Lachlan Hunt

More information about the microformats-discuss mailing list