Bob,
It seems to me that the most semantically clear way to indicate in a machine-readable way that two herbarium sheets are duplicates would be to assert that they have the same dwc:individualID.  individualID is defined as "An identifier for an individual or named group of individual organisms represented in the Occurrence" so asserting that two occurrences represent the same individual or named group of individual organisms pretty much exactly describes what duplicate specimens are.  I use this same approach to indicate that
http://bioimages.vanderbilt.edu/baskauf/67307
is an image of an acorn from the same tree:
http://bioimages.vanderbilt.edu/ind-baskauf/67304
as the bark image
http://bioimages.vanderbilt.edu/baskauf/67312
I won't say more here as I have written more extensively on this approach in Biodiversity Informatics 7:17-44 (https://journals.ku.edu/index.php/jbi/article/view/3664).  You can also look at the RDF associated with those GUIDs to see what I mean.  Solving this problem is also one of the reasons I have proposed adding the class Individual to DwC (i.e. so that the individuals that are the object of dwc:individualID can be rdfs:type'd using a well-known vocabulary and therefore be "understood" by linked data clients).

Steve

Bob Morris wrote:
http://rs.tdwg.org/dwc/terms/index.htm#associatedOccurrences   carries
this description:

associatedOccurrences
Identifier:	http://rs.tdwg.org/dwc/terms/associatedOccurrences
Class:	http://rs.tdwg.org/dwc/terms/Occurrence
Definition:	A list (concatenated and separated) of identifiers of
other Occurrence records and their associations to this Occurrence.
Comment:	Example: "sibling of FMNH:Mammal:1234; sibling of
FMNH:Mammal:1235". For discussion see
http://code.google.com/p/darwincore/wiki/Occurrence
Details:	associatedOccurrences

My questions:
a.  Are the names of the associations, and/or the syntax of the value
meant to be community defined?
b. If no to a. , where are those definitions? If yes, Have any
communities defined any names and syntax? I am especially interested
in "duplicate of" in the case of herbarium sheets."
c. (May share an answer with b.) Is there any use being made by anyone
in which associatedOccurrences is designed to have machine-readable
values.  If yes, where?

Thanks
Bob



  

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