To determine the genotype of a complete or partial influenza virus genome, a script is executed that first establishes the lineage of each viral gene segment. The genotype will be created by the sequential incorporation of the lineages for each of the eight segments, arranged per convention as shown in Table 1 . If a lineage does not meet the thresholds specified (95% default for both identity and coverage), the lineage will be assigned an asterisk ( Ã ) indicating the query sequence does not meet criteria and may be from a new lineage. If no BLAST results are found a blank lineage will be displayed. If all segments belong to known genotypes, the genotype of the query genomic sequence will be provided as output. The resulting genotype can be compared to previously identified genotypes in the Genotype database. This analysis can reveal reassortment events and host switching. If the genotype determined by FluGenome is not found in the Genotype database, the genome will be flagged as a virus with a potentially new genotype. Viral genotypes reported as new by FluGenome can simply result from identification of a gene from a novel phylogenetically defined lineage or the presence of genes from known lineages in novel combinations.