Word spelling
https://gcc.gnu.org/codingconventions.html#Spelling
Commit message guideline
https://github.com/angular/angular/blob/22b96b9/CONTRIBUTING.md#-commit-message-guidelines
Doxygen guide
https://llvm.org/docs/CodingStandards.html#doxygen-use-in-documentation-comments (but prefer @tag over \tag)
https://caiorss.github.io/C-Cpp-Notes/Doxygen-documentation.html (more tags, rarely used)
GitHub Markdown drop-down block
https://gist.github.com/citrusui/07978f14b11adada364ff901e27c7f61