Security.txt displays the security.txt and humans.txt files for a website if available.
security.txt is a proposed standard that provides a means for websites and software authors to define their security policies. This is useful to security researchers or anyone who would like to disclose a vulnerability to the website or software owners properly.
humans.txt is a less formal initiative for providing human-readable information about the website's authors.
As you browse the web and navigate to different websites, the browser extension checks the website to see if it supports either type of file. If it does, an Info icon is shown in the URL bar. You can click this icon to view more details about the text files that were located.