citationType field has inconsistent casing

[MattBlissett]

Untyped enumerations mean incomplete search results:

• https://api.gbif.org/v1/literature/search?limit=0&facet=citationType
• https://api.gbif.org/v1/literature/search?citationType=generic
• https://api.gbif.org/v1/literature/search?citationType=Generic

Maybe this should be an enumeration?

[dnoesgaard]

I probably had a typo somewhere at some point. I've corrected the "Generic" ones to "generic". But it would be nice if the crawler used an enum.

[timrobertson100]

A vocabulary might be appropriate, where the content crawler downloaded the full vocabulary on each run, allowing us to expand and add synonyms without code changes.

[dnoesgaard]

That sounds interesting—and like something that could work for other fields as well, e.g. topics

[timrobertson100]

and like something that could work for other fields as well, e.g. topics

Yes, plus it provides the definition of what the terms actually mean, should anyone be confused (e.g. future versions of ourselves).

[MattBlissett]

Note three other fields already have enumerations, LiteratureRelevance, LiteratureTopic and LiteratureType: https://gbif.github.io/gbif-api/apidocs/org/gbif/api/model/literature/package-frame.html