SwissProt/UniProt

Code	Meaning	Description
ID	Identification	Contains identifying information and characteristics of the sequence
AC	Accession number(s)	Release-to-release stable identifiers
DT	Date	When the entry was created, or when the sequence or annotation was modified
DE	Description	The name of the protein, often a function indicator
GN	Gene name(s)	The gene(s) that code for the protein
OS	Organism species	The organism from which the sequence is derived
OG	Organelle	If the sequence is non-chromosomal in origin
OC	Organism classification	The taxonomic class to which the organism belongs
OX	Taxonomy x-reference(s)	The NCBI TaxID for the OC line
RN	Reference number	The sequential number of the literature citation within the entry
RP	Reference position	The type of data, and the position in the sequence to which the citation refers
RC	Reference comment(s)	Comments relevant to the reference cited
RX	Reference x-reference(s)	Bibliographic cross-reference, such as PubMed ID
RA	Reference authors	Authors of the citation
RT	Reference title	Title of the citation
RL	Reference location	Source of the citation, such as journal, book, or unpublished data
CC	Comments	Free text notes about the protein
DR	Database x-references	Pointers to sources or related information for the entry
KW	Keywords	Indexable indicator of function, structure, or other information
FT	Feature table	Annotation of specific residues of the sequence
SQ	Sequence header	Marks the beginning of the sequence and provides summary data
(no code)	Sequence data	The sequence itself
//	Termination line	End of entry