folder permission

My current shared space folders are as follows:

/Share/Room

/Share/Room/test

I want users to be able to freely create files and folders in /Share/Room and delete things themselves, so I've granted them all read and write permissions, including "delete and delete subfolders" permissions, but no delete permission.

In /Share/Room/test, I want users to only have read permissions, not write or delete. Therefore, I've granted them read-only permissions, deny "delete" or "delete and delete subfolders" permissions.

However, I've found that users can still delete this folder. How can I solve this problem?

What is the actual difference between "delete and delete subfolders" and "delete"?