During November 2025, Tmtk contributed to the koreader/koreaderhub.io.git repository by implementing Vietnamese localization for the KOReader User Guide, making the documentation more accessible to Vietnamese-speaking users. Leveraging PO files and the Weblate platform, Tmtk established a collaborative translation workflow that tracks progress at the string level, reaching 11.1% completion. The work included updating UI strings and ensuring consistency across localized content, while also documenting the process for future contributors. Although the scope was focused on a single feature, the approach demonstrated a methodical application of localization, translation, and documentation skills, laying groundwork for ongoing internationalization efforts.