I agree. It might be worth looking at the dates expressed in the (UK) 
National Council on Archives 'Rules for the Construction of Personal, 
Place and Corporate Names' (section 2.5A) 
<>. This document 
expresses types of uncertain dates that archivists use when describing 
the lifetime of people and organisations, but they also apply to 
creation dates which are often uncertain in archive and manuscript 
collections. The dates are not expressed as machine readable dates, but 
they do offer a representation of what archivists need to be able to 

These links from the Archives Hub (a union catalogue of archives in UK 
Higher Education institutions) also show how some archivists are 
attempting to encode uncertain dates at present: 
<> and 


Matthew Beacom wrote:
> I think that Rebecca has suggested a nice expansion or generalization 
> of the problem raised by Priscilla's original message.  Developing 
> conventions (and wide agreement in usage) for such uncertain or 
> otherwise problematic dates would be very helpful for a wide range of 
> users.
> I like the idea of seeing what others are doing, too.
> Matthew
> At 6/19/2006 02:43 PM, Rebecca S. Guenther wrote:
>> ISO 8601 has limited ability to express a lot of types of dates,
>> especially some needed for cultural heritage objects, like those that 
>> are
>> questionable, approximate, etc. Perhaps we should come up with some 
>> conventions. I looked at this a few years ago in the context of some
>> Dublin Core work and could dig up my notes if needed on the 
>> limitations of
>> 8601. There has been little consensus on conventions for these kinds of
>> uncertain dates. So it may be prudent to establish some for PREMIS 
>> perhaps
>> based on what other efforts may be using.
>> Rebecca

Susan Thomas
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Oxford University Library Services
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