Updated FTP location. We adopted the method used in the O-Pair article to validate the FDR calculations of O-glycopeptide search in MS-Decipher. The detailed description of the method was provided in the ‘Methods’ and ‘Evaluating O-Pair Search performance’ parts of O-Pair article (Lu et al., 2020). The results were firstly filtered for Target hits and GPSM (glycopeptide-spectrum match)-level q-value < 0.01 and score > 0. And the ‘Estimated FDRs’ were calculated by dividing the number of total GPSM by the number of GPSM, whose sequence matched with the entrapment proteins.