As of March 2018, there were 141,000 prokaryotic genomes in the Assembly database. As this database grows, misassigned prokaryotic genomes becomes a serious problem. Taxonomy misassignment can occur through simple submission error or can accumulate as new information adds greater specification to the taxonomic tree.
A paper in the International Journal of Systematic and Evolutionary Microbiology presents the method NCBI scientists used to verify taxonomic identities in prokaryotic genomes. The authors used an Average Nucleotide Identity method with optimum threshold ranges for prokaryotic taxa to review all prokaryotic genome assemblies in GenBank. This method relies on Type strain information and is one outcome of a 2015 workshop involving several important parties in the bacteriology community.