This query parameter is an integer representing the number of recursive levels of folders and documents that the response object should include. The default value if the parameter is not set is 0, which means the response won't include any document or subfolder. Nested documents and subfolders are invalid when trying to create or update folders, so if the purpose of this request is to get a base folder object to then modify it using the PUT method, this parameter should be set to '0', or skipped.