What changes are needed to support a flexible taxonomic hierarchy?

[mdoering]

There are more and more issues with limiting our taxonomic backbone to the major Linnean ranks only. COL is including many more intermediate ranks these days and we could do the same for GBIF. But that poses all kinds of problems to how we deal with the taxonomy for occurrences.

What would be needed to support a flexible number of ranks as the classification for all occurrences?

Ranks would still be an ordered enumeration, but the name parser ranks have been growing considerably since we last ported them to the GBIF API. A flexible parent child based hierarchy could then include any of these ranks and also have multiple unranked or other taxa in between at any place in the hierarchy.

The version 2 name matching response format would not be different, but would potentially contain more taxa with any of the ranks in the classification, e.g.: https://api.gbif.org/v1/species/match2?name=Poa%20annua