Otherwise it'll complain for not finding any message. `defineMessage` ensures that React i18n static code collector is able to find the messages. References ---------- This pull request is part of the [FC-0012 project](https://openedx.atlassian.net/l/cp/XGS0iCcQ) which is sparked by the [Translation Infrastructure update OEP-58](https://open-edx-proposals.readthedocs.io/en/latest/architectural-decisions/oep-0058-arch-translations-management.html#specification). Check the links above for full information about the overall project.