Restriction fragment length polymorphism (RFLP) patterns can be used to classify type 2 PRRSV. A classification tool has been developed to make RFLP pattern assignments. Executable code and documentation may be found here. The tool supports FASTA file format as input. RFLP type is appended to the end of sequence header/s. If the appended value is "na" or "null", RFLP typing failed (ie this tool only works on type 2 ORF5 PRRSV).