Windows Integrity Levels (or WIC) is a system that can label an object with an integrity level. There are six such levels:

  1. Trusted Installer
  2. System
  3. High
  4. Medium
  5. Low
  6. Untrusted

WIC is available on Vista and Windows Server 2008.

Mark Minasi has an interesting article about it and a tool that allows you to work with these levels. The tool, chml, has more options than the built-in icacls.exe command. Check out the article here.