No, its not only immutable things on the stack. I mean if you include a literal constant string such as "MIT LICENSE", that is part of the compiled binary file. So it is unchangeable. Because you cannot change a literal, a "1" is always a "1" in the compiled binary file. And those are basically read only by their nature and loaded into the stack. I think or guess in C it is the same. Or any language for that matter.

I started to think I was hallucinating. I guess what I was thinking is this part https://en.wikipedia.org/wiki/Data_segment . There are read-only data segments too.