Semi related asking the wizard of HN. I recall reading a similar trick whereby one can embed a github key/token/api key/??? In a source file in one's repository

Semi related asking the wizard of HN. I recall reading a similar trick whereby one can embed a github key/token/api key/??? In a source file in one's repository and then if your code ever is stolen and pushed to github then you will receive a notification because github will revoke the token. Does this or similar ring a bell for anyone?