Add comments about dwciri equivalents

[tucotuco]

For each term that has a dwciri equivalent, include in the Comments for that term an explanation that the dwciri version exists what it is for. The comments should be consistent in wording. There should be one comment pattern for a dwciri term that is expected to have an IRI that points to a value in a controlled vocabularies, and another pattern for a dwciri term that is expected to have an IRI that points to other than a controlled vocabulary. Here are to draft options two elicit comments and suggestions.

"This term accepts a string as a value and has a counterpart with the same name in the dwciri namespace that is intended to be used only with a global unique identifier (specifically, an IRI) that points to a specific value in a controlled vocabulary. For this latter purpose, the dwciri version of the term is recommended to be populated."

"This term accepts a string as a value and has a counterpart with the same name in the dwciri namespace that is intended to be used only with a global unique identifier (specifically, an IRI). For this latter purpose, the dwciri version of the term is recommended to be populated."

[sformel-usgs]

We [the GBIF-US node, @albenson-usgs and myself] support the addition of these comments. Here is another suggestion, although it might be oversimplifying the idea:

"This term, in the dwc namespace, accepts a string as a value. However, the same term in the dwciri namespace accepts an IRI, from a controlled vocabulary, as a value."

[tucotuco]

The current list includes the following terms, but see #445 for possible additions:

behavior
dataGeneralizations
degreeOfEstablishment
disposition
establishmentMeans
fieldNotes
fieldNumber
footprintSRS
footprintWKT
geodeticDatum
georeferencedBy
georeferenceProtocol
georeferenceSources
georeferenceVerificationStatus
habitat
identificationQualifier
identificationVerificationStatus
identifiedBy
informationWithheld
language
lifeStage
locationAccordingTo
measurementDeterminedBy
measurementMethod
measurementType
measurementUnit
measurementValue
occurrenceStatus
organismQuantityType
pathway
preparations
recordedBy
recordNumber
reproductiveCondition
sampleSizeUnit
samplingProtocol
sex
typeStatus
verbatimCoordinateSystem
verbatimSRS
verticalDatum