[Esip-preserve] Identifiers Use Cases

[Curt Tilmes]

I had a few discussions with Al Fleig and Brian Duggan about how to
handle these.  (And many previous with Ruth, Bruces, etc.)

I added some info to the wiki [1].  I put my definitions (that differ
slightly from Bruce B's).  In particular, I defined Open vs. Closed
data sets.  My concern is that I believe that our identifiers schemes
must fully qualify the precise granule membership of the cited data
set at the time the researcher downloaded the data from an open data
set.  I think this isn't done in general today.

I also distinguished Data Type from Data Set, and tried to define Data
Version (which is also slightly different from Bruce B. and Greg
Janee).

I wrote a more general use case [2], with some place holders for
different things we must handle, and reworked the DOI case to map to
those place holders, and added some PURL stuff as well.

Curt

[1]
http://wiki.esipfed.org/wiki/index.php/Interagency_Data_Stewardship/Identifiers

[2]
http://wiki.esipfed.org/wiki/index.php/Interagency_Data_Stewardship/Identifiers/UseCases