Sequence Info. This package defines class BioSeq, which represents biological sequences, and class SeqInfo, which describes general information about these sequences. The administrative data associated with database entries are defined in EntryInfo. The biological classes of sequence NSDBSeq, which is for nucleotide sequences, and PIDSeq, which is for protein sequences, are subclasses of BioSeq. VirtualSeq and PhysicalSeq are storage classes of sequence, that is, virtual or literal.