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Add page and line break symbols to a score in Logic Pro for Mac
You can add page and line break symbols (and No Page Break and No Line Break events) from the Part box. Once added to the score, they cannot be moved automatically (when you alter the Layout project settings, resize the window, and so on).

You can overrule the Page Break, Line Break, No Page Break, and No Line Break events with the Layout tool.
Line breaks and individual staff margins can be determined for each score set, and also for each of the extracted parts. For more information, see Line and page breaks in a score set.
The Part box is available when Enable Complete Features is selected in Logic Pro > Settings > Advanced.