I'm guessing you're referring to the "Verified Publisher" blue checkmark next to the publisher's name and domain name, which proves the publisher owns the domain name and has 6+ months in the marketplace? https://code.visualstudio.com/docs/configure/extensions/exte...
(Separately, it doesn't help that MS doesn't allow VS Code forks to use the official marketplace, including as verified publisher doesn't seem to exist there - example: https://open-vsx.org/extension/esbenp/prettier-vscode )