The "keys" often listed in GitHub Readme files, such as those found in the Rupesh-C repository or various generic KMS client keys
A Microsoft Office product key is a 25-character code that is required to activate a copy of Microsoft Office. The product key is used to verify that the software has been purchased and to prevent unauthorized use. The product key is usually provided with the purchase of the software or can be found on the packaging or in the confirmation email.
: Many gists provide the public KMS key for Office 2021 (e.g., FXYTK-NJJ8C-GB6DW-3DYQT-6F7TH ) which is used to point an Office installation toward a licensing server.