From File attachments on issues and pull requests - GitHub Docs I understand that ODF files are not supported, while they are an ISO standard supported by proprietary and FOSS office suites. I am a Linux user, and the native file format of my docs is ODF. Although I can save in the non standard and proprietary OOXML file formats (DOCX, XLSX and PPTX), I would like to avoid them because of the flaws and vulnerabilities associated with those formats. GitHub should support ODF as much as OOXML. Best regards.