Supplemental Records are articles from the same study, usually published in another journal. In the example below, you can see the articles are very similar but the publication volume is different, as well as the year it was published (2019 vs. 2018):
Supplemental Records are automatically identified by the system during deduplication and they are removed prior to screening (i.e., they are excluded from the screening process). The Primary Article, however, is included in Abstract Screening. You can see this on the PRISMA in the “Identification” section under “Records Removed Before Screening”:
If you click on the “Not a Supplemental Record” button while viewing the Supplemental Records, it will make the non-primary article eligible for screening (i.e., move it to “Pending Screening” under Abstract Screening):
