[tdwg-content] Delimiters for Darwin Core list-type terms

[Markus Döring]

Hi John et al.,

I would like to see a single recommended default delimiter, preferrably the semicolon as its natural and hardly used in values. 
For dwc archives there is a multiValueDelimiter attribute for every term mapping that allows to declare other delimiters if needed.

Currently it is hardly possible to detect multi values in a field and you can just test for some often used ones but even then you never know if they were meant to be delimiters.
Having a single default value helps to get the idea of multi values across and make it a bit more accessible I believe.

dwc:vernacularName I would personally prefer to see as a single value term as it is mostly useful in combination with a locale and rarely is shared on its own.
Seeing dwc:typeStatus being a multi value term also feels wrong as the name is in singluar while the others carry the multi value nature in the name already. 


Markus



n 07.10.2013, at 12:28, John Wieczorek wrote:

> Dear all,
> 
> On the list of pending Darwin Core issues is a topic of general
> concern about terms that could or do recommend the concatenation and
> delimiting of a list of values. The specific issue was submitted on
> the Darwin Core Project site at
> https://code.google.com/p/darwincore/issues/detail?id=168. Right now
> there is variation in the recommendations of distinct terms.
> 
> The Darwin Core terms that could be used to hold lists include the
> following (use the index at
> http://rs.tdwg.org/dwc/terms/index.htm#theterms to find and see the
> details of each of these):
> 
> informationWithheld
> dataGeneralizations
> dynamicProperties
> recordedBy
> preparations
> otherCatalogNumbers
> previousIdentifications
> associatedMedia
> associatedReferences
> associatedOccurrences
> associatedSequences
> associatedTaxa
> higherGeography
> georeferenceSources
> typeStatus
> higherClassification
> vernacularName
> 
> There are some issues. Many terms do not show examples. Most of those
> that do show examples recommend semi-colon (';') -
> associatedOccurrences, recordedBy, preparations, otherCatalogNumbers,
> previousIdentifications, higherGeography, georeferenceSources, and
> higherClassification, The example for higherClassification does not
> have spaces after the semi-colon while all others do.
> 
> Terms that could hold a list of URLs would require a delimiter that
> would be an invalid part of a URL unless it was escaped. This
> precludes comma (','), semi-colon (';'), and colon (':'), among
> others. One possibility here might be the vertical bar or "pipe"
> ('|').
> 
> The term dynamicProperties is meant to take key-value pairs. The
> examples suggest the format key=value, with any list delimited by a
> semi-colon, for example, "tragusLengthInMeters=0.014;
> weightInGrams=120". The example for associatedTaxa also shows a
> key-value pair ("host: Quercus alba"), but it is formatted differently
> from the examples for dynamicProperties. There are other terms, such
> as vernacularName, which could potentially also take a key-value pair,
> though it is not currently recommended to be a list.
> 
> Please ignore the issue of whether the idea of list-type terms is a
> good idea or not - that is not the issue we're trying to resolve here.
> Instead, the issue is whether a consistent recommendation can be made
> for how to delimit the values in a list. And if not a consistent
> recommendation, can we make specific recommendations for distinct
> terms? If specific recommendations can be made for a term, should that
> be reflected in examples within the term definitions, or should such
> recommendations reside only in Type 3 supplementary documentation such
> as that which can be found on the Darwin Core Project site at, for
> example, https://code.google.com/p/darwincore/wiki/Occurrence#associatedSequences?
> Should some of these terms have specific recommendations to contain
> only single values (e.g., vernacularName), in which case they are not
> really viable in Simple Darwin Core?
> 
> Cheers,
> 
> John
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