| The field codes found in EMBL sequence flat files are used to help organize the information for human readability and machine-based parsing. There are several field codes found in an EMBL sequence flat file, and they are designated with a two-letter abbreviation. Table 2-2 summarizes the content of each field code. Table 2-2. EMBL field definitions | Line code | Content | | ID | Identification | | AC | Accession number(s) | | SV | New sequence identifier | | DT | Date | | DE | Description | | KW | Keyword | | OS | Organism species | | OC | Organism classification | | OG | Organelle | | RN | Reference number | | RC | Reference comment(s) | | RP | Reference positions | | RX | Reference cross-reference(s) | | RA | Reference authors | | RT | Reference title | | RL | Reference location | | DR | Database cross-references | | FH | Feature table header | | FT | Feature table data | | CC | Comments or notes | | XX | Spacer line | | SQ | Sequence header | | | (Blanks) Sequence data | | // | Termination line | |