Hi

I have made a short video explaining how to create a FilledRegion inside a sheet.
Revit doesn't allow for us to create a FilledRegion in the sheet by nature, but with this neet work-around it's possible to create a FilledRegion (hatch) that is easy to drag to the correct size in order to hide/mask parts of the model shown in the sheet.
https://youtu.be/RjYzdHNMQKw

Hope it will come in handyfor someone