Earlier quoted context omitted.
We're talking in English, not in Go. The meaning doesn't change that much because of using uppercase initials. What you're referring to has already been consolidated as "source available".
I'm not a native speaker, but to me "open" sounds like it fits to the case when I can see the code. Am I speaking in Go?
As an example, you could describe a spinning disk hard drive as "RAM" because it's a memory device you can randomly access. That would meet the dictionary definitions of "random", "access", and "memory". And yet, everyone would be annoyed with you for doing so. "I have 16TB of RAM in my computer!" "No you don't, Kebab. Stop saying that!"