One experiment record represents one curated experimental entry linked to a paper and a peptide.
Blank values indicate that the information was not reported in the source article, has not yet been curated, or could not be normalized confidently.
Paper ID identifies one publication, Peptide ID identifies one peptide entry, and Experiment ID identifies one curated experimental record. Multiple experiments can map to the same paper and peptide.
Named residue annotations such as ORN are stored directly in the noncanonical residues field when available.