What version of Markdown do these guidelines use?

These coding standards are written using CommonMark, and <a> HTML anchors.

We are considering the following extensions from GitHub Flavored Markdown (GFM):

• fenced code blocks (consistently using indented vs. fenced is under discussion)
• tables (none yet but we'll likely need them, and this is a GFM extension)

Avoid other HTML tags and other extensions.

Note: We are not yet consistent with this style.