Comment by wafflemaker

I made my own macro* to encapsulate the currently selected text in SOURCE \END_SOURCE tags. Now you're telling me there was a keyboard shortcut for that?

What else I don't know about emacs?

*It was my first macro/function and while creating it I've learned that 1. It wasn't that hard and 2. With help of an LLM you can program emacs a little even without deep knowledge of elisp. Though LLMs suggest very unreadable elisp code and you have to rewrite everything.