For example, HUM and PRI represent human and primate respectively. The the biological features contained in the entry are briefly described in a specified order. This line is composed of the scientific name of the source organism, molecular type of the template, and name of the product encoded in the sequence. Keywords such as gene name and product name are noted in this line. There is no restriction concerning the choice of terms.
Some entries contain no keywords even if they have significant biological features.
The scientific name of the source organism is registered to, and determined by, Unified Taxonomy database maintained by GenBank. Biological features and experimental conditions are often implied in the title of the paper. In principle, the features are annotated based on the report given by the submitters, and DDBJ will correct or modify the descriptions to adapt them to the format. Thus, the contents of each flat file may vary depending on the information given by the submitters. CDS key, which defines the coding region for a protein, is most frequently used among the feature keys.