See https://north-road.com/2019/01/14/on-custom-layout-checks-in-qgis-3-6-and-how-they-can-do-your-work-for-you/
This feature was funded by SMEC/SJ
This feature was developed by Nyall Dawson (North Road)
This application was created by Kartoza (Pty) Ltd. Available on GitHub! Version: 2.3.1