I can mark mutliple lines an press M + ; (meta plus semikolon). Then a
# is added in front of each line. This works in a “normal” org file.
But when the point is in a source block (
#+end_src) in an org file the M + ; doesn’t work. No reaction. No error.
I think we are a bit off topic. However, I cannot confirm this. If the source block specify the language (eg,
M-; will add the correct comment notation (in the given example, it will use as comment
;). If a block is selected, it will comment-out that block, if not, it will put the comment notation at the end of the line.
The language specifier was missing. That was the solution. Thanks.