Worked on stabilizing HTML serialization in the DS4SD/docling-core repository, focusing on correcting how singleton meta tags are output. Addressed a critical bug by updating the serialization logic to apply self-closing syntax to singleton tags, specifically meta charset and generator, ensuring compliance with HTML5 standards. This change reduced the generation of invalid HTML and improved compatibility with various parsers, leading to more reliable downstream rendering. The work involved code refactoring and careful updates in both Python and HTML, with clear, traceable commits that demonstrated attention to standards compliance and measurable impact on the robustness of HTML output.