General feature format
In bioinformatics, the general feature format (gene-finding format, generic feature format, GFF) is a file format used for describing genes and other features of DNA, RNA and protein sequences. == GFF Versions == The following versions of GFF exist: General Feature Format Version 2, generally deprecated Gene Transfer Format 2.2, a derivative used by Ensembl Generic Feature Format Version 3 Genome Variation Format, with additional pragmas and attributes for sequence_alteration features GFF2/GTF had a number of deficiencies, notably that it can only represent two-level feature hierarchies and thus cannot handle the three-level hierarchy of gene → transcript → exon.