I need to download the refseq files for viral genomes from the ncbi database. I found the ftp download link (ftp://ftp.ncbi.nih.gov/refseq/release/viral/) with the files listed below. I've tried to find out what each file is, but I can't find anywhere the meaning of the numbers. What is the difference between viral.1.1.genomic.fna.gz and viral.2.1.genomic.fna.gz? They all seem to be uploaded on the same date, so they can't be different versions. I tried their README (ftp://ftp.ncbi.nih.gov/refseq/release/release-catalog/README) but I don't see the information I need.
List of files:
Can anyone tell me what the difference is or where to find this information? Thanks a lot!