DFSG
The DFSG, or Debian Free Software Guidelines, are a set of criteria that software Licenses must comply with to form part of the Debian system. They have since been adopted with minor changes to form the Open Source Definition v1.9 at the Open Source Initiative.

CLiki is not part of the Debian project, but the DFSG is a convenient definition of what we mean by `free', so we have adopted these guidelines as criteria for software to be listed here.