include "ignore this xxx" in the sample and taxon sheets

[tobiasgf]

User often have control samples or other samples they wish to exclude from the GBIF published dataset, but wish to keep in the upload data for completeness. The same goes for specific taxa (contaminants). Could we have an optional "ignore" field for both the sample and taxon sheets, that would mean that any content in that field would exclude the corresponding row entirely from the data that eventually goes into the DwC-A?

Potential problems:

• Excluding taxa/sequences may heavily influence the total read count per sample if this number is calculated after the removal.

[tobiasgf]

The new field for the taxon sheet could be called e.g. excludedTaxon, exclusionCriterion, or similar. (or do we already have something that could be used (with caution): e.g. identificationRemarks Values could be: Known contaminantion Suspected contamination Spurious detection Habitat mismatch non-indigenous Suspicious sequence non-target low abundance low frequency positive control other ...

For the sample data we could include the two existing fields: neg_cont_type and pos_cont_type, and exclude (from the generated DwC) all samples that carry any value in either of these fields. Values for neg_cont_type could be: field blank, blank filter, extraction blank, PCR non template control other

Values for pos_cont_type could be free text (a string of taxon names, the name of a known positive control mock sample, etc.