Fig. 2
From: Taxallnomy: an extension of NCBI Taxonomy that produces a hierarchically complete taxonomic tree
Rank assignment step. See text for a detailed explanation. a Set of rules followed by the algorithm to assign a single rank to an unranked taxon with candidate ranks. b Some examples of complex situations faced by the algorithm and the way it solves the rank assignment, the tree restructuring, and the node naming. Candidate ranks of an unranked taxon are in balloons. Square nodes represent taxa originally found in NCBI Taxonomy. Names assigned to nodes ranked (type 1) or created (types 2 and 3) by the algorithm are shown in gray balloons