History Microformat (was Re: [uf-discuss] Dated currency examples?)

Kevin Marks kmarks at technorati.com
Mon Oct 2 19:50:31 PDT 2006

On Sep 25, 2006, at 10:03 AM, Jeremy Boggs wrote:
> i would be very interested in helping to explore a "history" 
> microformat. In my spare time, I've been collecting examples of 
> history timelines, after discussions a few months ago on this list 
> about the inability of using hCalendar to mark up before common era 
> dates, and other considerations for marking up historical dates and 
> spans of time.[1] I've collected examples of uses of BCE dates and 
> timelines in general, but I could easily expand the scope of my 
> inquiry.

Starting to collect these at history-examples on the wiki, and making 
notes at history-brainstorming would be a useful start.

> Like Tantek says, a history microformat might help address the issue 
> of past currency values, as well as help markup a host of other 
> historical information: both secondary sources (biographies, 
> timelines, articles, genealogy) and primary sources (census records, 
> newspapers, letters, diaries, probate records, etc...). I may be 
> biased about this (I'm a history PhD student. And, I understand that 
> we would need to collect real-world examples first before moving on. 
> I'd be happy to share what I've collected so far, and help out any way 
> I can, if the community thinks it is worthwhile.

Price exchanges are a complex subject, and we should be wary of either 
over-simplifying the real world, or bringing too much of its own 
complexity with us.

Some prices fluctuate minute by minute (think stock markets), some on a 
slower basis. For most currencies, people are willing to consider 
prices in that currency as usably stable, though obviously the date it 
was offered is a useful secondary piece of information.

Comparing prices between countries and even more so between eras is far 
more problematic, because of technological change affecting relative 
prices. I don't think we want to get into GDP deflators and Purchasing 
Power Parity if we can avoid having to. See this recent post for some 
of the complexities:


One thing that has come up several time here is a discussion of 
date/price series - comparing prices over time. That seems like a 
useful thing to consider in the light of composable date and price + 
currency formats.

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