GitHub Markdown – Highlight Deleted and Added Lines

githubmarkdown

How can I highlight deleted and added lines like in this comment? How do I make it look like a git diff?

Do I have to use HTML? Or is there some tricky syntax like strikethrough?

Best Answer

That is done by using a code block with the "diff" syntax. The raw markdown would look something like this:

One small step for 
```diff
-man
+humankind
```

I've made a gist also that demonstrates the code (click "Raw" to view the markdown).