The full serials permission is required in order to manage frequencies (subscription-frequencies.pl), which can be confusing for staff since managing numbering patters (subscription-numberpatterns.pl) does not thanks to bug 29608. It's unclear why managing frequencies should require more permissions than staff need to manage numbering patterns.
Also, the menu item appears if the staff member only has one sub-permission (such as receive_serials), but if they click on it, it says that they don't have access. We should hide the menu item if they don't have permission to access it. To recreate: 1. Give a patron minimal permissions - catalogue - receive_serials 2. Access the staff interface with that patron 3. Go to Serials --> Manage frequencies appears in the left side menu 4. Click Manage frequencies --> Error: You do not have permission to access this page.