[markdown][clarification] what does CL mean?

From the html version of the [markdown style guide](https://google.github.io/styleguide/docguide/style.html#better-is-better-than-best), based on [style.md](https://github.com/google/styleguide/blob/8c4da230fc15e01e0ba3545c8a6ff55bc3da4649/docguide/style.md?plain=1#L72):
> Set lower standards for each CL, so that **more such CLs** can happen.

I do not work at Google, but what does CL mean? It is not explained in the documentation and searching for the CL acronym online does not point me in a sensible direction.

## Actual result
CL without explanation.

## Expected result
A clarification what CL means, since this is the first time the acronym is used.