Genome Variation Format
The Genome Variation Format (GVF) is a file format for describing sequence variants at nucleotide resolution relative to a reference genome. It is an extension of the widely used Generic Feature Format version 3 (GFF3) standard for describing genome annotation data. The features described by GVF are typed using the Sequence Ontology which means that the terminology being used to describe the data is standardized, and organized by pre-specified relationships. The GVF format has the same nine-column tab delimited format as GFF3 and all of the requirements and restrictions specified for GFF3 apply to the GVF specification as well. The attribute specification structure of the GFF3 format allows extensibility in specifying feature-specific data for different types of features and it is this extensibility that GVF capitalizes on in defining sequence alteration specific data types.