1. She also explained that Thomas had a secret code name.

2. We're government agents now, we should have secret code names.

3. The secret code of the computer was engraved in your bracelets.

4. Writing Anagrammatic versions of a word for a "secret code" game

5. Whitaker's Almanack, which gave Holmes the key to the secret code in The Valley of Fear.

6. In an organization, a Cryptographer is responsible for developing systems that can encrypt sensitive information. They use algorithms and cyphers (messages written in secret code) to achieve this