How do comments work in COBOL?

Tried // and # like other languages. Compiler yelled. What is the actual way to comment a line? And can I do mid-line comments?

Column 7 with * comments the whole line (fixed format). Or *> for a free-form / inline style comment depending on your compiler options.

On z/OS Enterprise COBOL, * in col 7 is what most of our old code uses.

• in column 7 worked. I had it in column 8 like an idiot.