docs/data/reusables/code-scanning/custom-configuration-file.md

The configuration file can be located within the repository you are analyzing, or in an external repository. Using an external repository allows you to specify configuration options for multiple repositories in a single place. When you reference a configuration file located in an external repository, you can use the OWNER/REPOSITORY/FILENAME@BRANCH syntax. For example, octo-org/shared/codeql-config.yml@main.