Duncan refined documentation for the symfony/symfony repository, focusing on updating branding terminology to reflect the transition from OhMySMTP to MailPace. He identified and corrected the use of "rebanded" to the accurate "re-branded" in the README, ensuring consistency and clarity for users referencing the package. Working exclusively with Markdown and leveraging version control best practices, Duncan’s targeted change improved the accuracy of public-facing documentation and reduced potential confusion for both users and support teams. While the scope was limited to a single feature over one month, the update contributed to better onboarding and documentation hygiene within the Symfony project.