Although in proteomics, sequence database searching is the dominant strategy to annotate MS/MS spectra , the usage of spectral libraries has become increasingly popular for the analysis of peptide MS/MS data as well in recent years . Spectral library searching is more sensitive than sequence database searching, achieving a higher rate of spectrum identifications , and results from spectral library searching and sequence database searching can be combined to maximize the number of identified MS/MS spectra . This increased sensitivity is especially relevant for the analysis of data-independent acquisition (DIA) experiments, where mixtures of analytes within large, pre-specified mass ranges are measured, in contrast to data-dependent acquisition (DDA), which attempts to isolate and measure individual analytes . The resulting complex DIA spectra contain signals from multiple peptides, and most DIA analysis tools require detailed MS/MS fragmentation patterns from reference spectral libraries to annotate peptides.