Where does the peer review indicator come from?
Answer
According to Ex Libris documentation:
"The relevant Alma CZ records for journals have been enriched with a peer review indicator, which is based on Ulrich's (500 $a Refereed/Peer-reviewed) setting."
The Open Access indicator is also coming from Ulrich's.
There's an August 2019 Idea Exchange entry about making the peer review indicator more accurate, which is currently under review. The problem with the current peer review notation is that it applies to anything from the peer reviewed journal, including book reviews, editorials, etc.
Another problem reported on the Primo-L listserv, is that journals that are not "refereed/peer-reviewed" are getting the indicator. For example, one title mentioned is: The journal of housing and community development. In Primo, the journal has the peer-reviewed indicator. However, in Ulrich's there is no indication this title is peer-reviewed.
Ex Libris relies on the vendor to let them know whether to include the Ulrich's (500 $a Refereed/Peer-reviewed) setting. This information may not always be accurate.