Hi Roger,

Could you attempt a concise definition of a UsageInstance we can all agree on then :)

Sure: Any occurrence of a NameString as it appears or is explicitly implied within some form of static documentation.

"NameString" refers to a string of textual characters meant to represent a name of biological organisms. This can be defined more restrictively to "ScientificNameString" (names that conform to one of a designated set of nomenclatural Codes), or more broadly to include vernacular NameStrings.

"static documentation" can be defined broadly, to include publications, databases, and any other form of documented medium of human communication. The "static" part means that it must represent a snapshot in time. In the case of dynamic databases, this would require a "date stamp" for each UsageInstance -- either for an individual record, or for a snapshot of the entire dataset.

The "explicitly implied" part addresses zoological-style nomenclatural listings along the lines of what Yde has sent to this list, where a genus is listed once as a header, and species epithets are enumerated below, explicitly implying a series of binomials, even if they are not actually printed on papaer as such.

The point is, the definition is highly flexible, yet mostly unambiguous (assuming sufficient metadata for identifying a documentation instance).

I think it only makes informatic sense to distinguish two "kinds" of GUID for taxonomic objects if the distinction between the objects is unambiguous. Given these NameStrings:

1. Aus Smith 1995 2. Xea Jones 2000 3. Aus bus Smith 1995 4. Xea bus (Smith 1995) Jones 2000 5. Xea ba (Smith 1995) Jones 2000

It is ambiguous whether there are three, four, or five distinct NameObjects represented (i.e., it is ambiguous whether #s 4 & 5 should get TaxonName GUIDs, or TaxonConcept GUIDs via SEC instances).

However, given this list:

1. "Aus" as it appears in Smith 1995 2. "Xea" as it appears in Jones 2000 3. "Aus bus" as it appears in Smith 1995 4. "Xea bus" as it appears in Jones 2000 5. "Xea" as it appears in Pyle 2005 6. "Xea ba" as it appears in Pyle 2005 7. "Xea" as it appears in ITIS Nov. 11, 2005 snapshot dataset 8. "Xea bus" as it appears in ITIS Nov. 11, 2005 snapshot dataset 9. "Xea ba" as it appears in ITIS Nov. 11, 2005 snapshot dataset

There is very little ambiguity that each item in this list gets its own GUID. Until a universal definition of a "NameObject" emerges, certain usage instances can serve as surrogates for basionyms (1, 2, 3), or botanical new combinations (4), or TaxonConcepts (1-6) -- in whatever way that a data manager needs or wishes to establish linkages among GUIDs (e.g., linking #s 4, 6, 8 & 9 to #3 via "is basionym of"; or linking #s 4, 6, 8 & 9 to #2 via "is combined with"; or linking #5 to #6, #2 to #4, and #1 to #3 via "contains").

Several people have expressed a desire for "simple" and "flexible", and I think this approach maximizes both.

Aloha, Rich