The primary PSI standard format for encoding the peptide/protein identifications that are derived from an MS proteomics experiment is mzIdentML. The version 1.1, considered as the first stable version, was released in 2011 and version 1.2 in 2017, adding features for workflows such as de novo sequencing, crosslinking, proteogenomics approaches and improved encoding of protein inference results. The mzIdentML format is widely implemented in over 35 software tools () and an encouraged (but not required) format at the ProteomeXchange data repositories, since it is one of the standard formats that can be used for performing "Complete" submissions (those where the identification data can be parsed and linked to the mass spectra by the receiving repository).