Which file attribute indicates a file which is required by the operating system?

The file attribute that indicates a file which is required by the operating system is typically referred to as the "System" attribute. This attribute is used to mark a file as a system file, meaning it is a file that is used by the operating system and should not be manipulated by the user. Here are the steps to identify this attribute:

1. Open the properties of the file: You can do this by right-clicking on the file and selecting "Properties" from the context menu.

2. In the Properties window, look for the "Attributes" section: This is usually located at the bottom of the window.

3. Check for the "System" attribute: If the "System" checkbox is checked, this indicates that the file is a system file.

Please note that not all operating systems display file attributes in the same way. The steps above are generally applicable to Windows operating systems. For other operating systems like Linux or MacOS, system files are usually hidden and require specific commands to view.