Verbose but extensible and explicitly defines all values (without breaking DRY):
<div class="currency"> <p class="figure"> <span class="code">code</span> <span class="sign">symbol</span> <span class="amount">12345</span> </p> </div>
"figure" is there to both explicitly associate the code, sign and amount but also allow the potential for more than one currency figure to be placed within the container. It does anticipate further development though and is the most easily dropped item at the early stage.
<div class="currency"> <span class="code">code</span> <span class="sign">symbol</span> <span class="amount">12345</span> </div>
Super shortened, relying on the parser to identify everything via implied order/structure:
Although the simplest solution, it has a notable vulnerability: some currencies have/had three-letter abbreviations for their currency sign, instead of a symbol. This would make it very difficult for a parser to accurately identify such a currency.
In addition, it should be noted that the order alone cannot be used to identify which parts are code, sign and amount; since many currencies are denoted with the sign after the number.
Super shortened, but specifying a currency code as a class:
<div class="currency ABC">12345$</div>
- we're talking about money - ISO standard implied,
- we're talking about the USD variety,
- we're talking fifty units of that money,
- a parser could work out the numbers and the symbol.
The biggest limitation I can see for that shorthand is that the currency code is not displayed visibly to human readers. The currency code is useful information to viewers and ideally should be displayed.
Shortened (including dropping 'figure', but explicitly defining and displaying the currency code. This would allow a parser to treat any remaining numbers as the amount; and any remaining a-z or symbol as the sign:
<div class="currency"> <span class="code">ABC</span>12345$</p> </div>
Charles Iliya Krempeaux
Maybe something like...
Pay me <abbr class="currency" title="CAD">$</abbr>5.00 now!
Although something like the the following might be better...
Pay me <span class="money"><abbr class="currency" title="CAD">$</abbr>5.00</span> now!
But it might be more semantic salt than is considered necessary. Just having the abbr with the class-currency near a number might be good enough. But that's open for discussion though.
Could pure HTML be sufficient?
<html lang="en-gb"> <p>My new T-Shirts cost £30, but it cost my friend in Canada <span lang="en-ca">$34</span></p> </html>
<p lang="nb">Den kanadiske prisen på t-skjorten var <span class="currency CAD">34 $</span>.</p>
<span class="money"><abbr class="currency" title="CAD eng">$</abbr><span class="amount">5.00</span></span>
In this format the wrapping would be "money" or something similar followed by either the actual "amount" or the "currency", depending on what rules your country/language follows in regards to the order. Since there can be a difference between different languages within countries I thought it might be a good idea to include that in the "currency" definition of the formating, eg., "CAD eng" or "CAD fr". It could also give sites that list multiple languages a way to differentiate when they show multiple prices.
The only microformat that I've noticed currency units in is hListing draft, and that deliberately shies away from parsing the actual values because it's too free-form in most existing Listing formats.
My own preference would be for something like:
<p class="money">This item costs <span class="currency">GBP</span> <span class="amount">10.00</span> </p>
Which with similar parsing rules to existing formats would also allow things like:
<p class="money"> It'll cost you <abbr class="currency" title="50.00">fifty</abbr> <abbr class="amount" title="GBP">quid</abbr> , mate! </p>
Or, a more complex example with multiple languages:
<p lang="en">Price: <span class="money"> <abbr class="currency" title="GBP">£</abbr> <span class="amount">1,250.00</span> </span> <span lang="fr" class="money"> (Prix: <span class="amount">1600,00</span> <abbr class="currency" title="EUR">€</abbr> ) </span> </p>