Fig. 6: number of MS2 spectra that are attributed to specific features.

a pLink, b StavroX and c Xi. Shown is the number of MS2 spectra annotated as CSMs, monolinks/looplinks/unmodified peptides, unvalidated PSMs with a score below the cut-off value for 5% FDR, decoy PSMs, and PSMs for which no information is known (unknown).