data.frame of 43 rows, with 2 columns:
rankid - a numeric rank id, consecutive
ranks - a comma separated vector of names that are considered equal to one another within the row
We use this data.frame to do data sorting/filtering based on the ordering of ranks.
Please let us know if there is a rank that occurs from one of the data
sources taxize that we don't have in rank_ref dataset.
Let us know if you disagree with the ordering of ranks.