I wish that markdown could be extended.

[ajtruckle]

🏷️ Discussion Type

Question

💬 Feature/Topic Area

Code Search and Navigation

Body

I wish that markdown could be extended.

1. ability to show line numbers if wanted.
2. ability to state the starting line number.
3. ability to indicate which lines of code to highlight in the block.

It is great that we can show code blocks and the syntax highlighting. But none of the rest.

I am able to format blocks of code using WordPress with EnlighterJS. It is a pity the richness of that could not be available here in markdown for GitHub Wiki documentation.

[onur-g]

It is a valid frustration, especially when comparing GitHub's native Markdown implementation in wikis and issues to dedicated blogging platforms or documentation tools like EnlighterJS.

GitHub relies on standard CommonMark and GitHub Flavored Markdown (GFM) parsers, which intentionally stick to the core spec for predictability and security across millions of repositories. While you can specify language identifiers for syntax highlighting (e.g., ```python), GFM deliberately omits presentation controls like explicit line numbers, custom start indices, or line highlighting ranges.

Unfortunately, extending the native markdown parser to support custom rendering attributes for code blocks is something the GitHub team has historically been very conservative about implementing directly in GFM. If you need this functionality today, your best workaround for GitHub Wiki documentation is to embed HTML <pre> and <code> blocks with custom CSS/classes if the wiki renderer allows raw HTML, or rely on external documentation generators (like VitePress, MkDocs, or Docusaurus) that hook into more feature-rich markdown extensions and render the output via GitHub Pages.

[AhmadHassan-BTed]

Well, you'll be happy to know that there are workarounds : )

1. If the code you want to show exists somewhere in a GitHub repository, don't write a markdown code block. Instead, navigate to the file, click the starting line number, hold Shift and click the ending line number. Copy that URL (press y to make it a permalink) and paste it directly into your Wiki. GitHub automatically expands the URL into a fully formatted code block with line numbers and highlights.
2. If the code isn't in a repo, use diff as your language tag. You can prepend lines with + (which highlights it green) or - (red) to visually draw attention to specific lines.