Code and change review are also closely related to our study, as we derived patch-rejection reasons directly from patch review comments. In its early years, code review or inspection was a formal process to detect software defects [30][31][32][33][34]. Studies have observed a 75:25 ratio of maintainability and functional problems fixed in code review [16][17]. Our work complements these studies with more detailed patch-rejection reasons identified from review comments. Bacchelli and Bird proposed that modern code review has become lightweight and focused more on small and incremental code changes [13]. They also found that in addition to finding defects, modern code review provides additional benefits such as knowledge transfer and team transparency [13]. Rigby and Bird studied contemporary peer review by investigating peer review processes in Android, Chromium, Bing, Microsoft Office, MS SQL, and internal projects of AMD [14]. They found that the characteristics of their review process ultimately converge regardless of the differences between these projects.