You call BS because the HTTP/1.1 standard calls pieces of text that contain the name of the software at the other end of the connection "comments"? (To those that didn't read the spec, it uses the word comment to refer to the values in the User-Agent, Server, and Via headers.)

It turns out these "comments" were a disaster and user agents are moving away from even providing them. You put "firefox" in the user-agent header, and web servers would read the comment and send you "your browser doesn't work" instead of the actual document. That did not make for a very compatible web... turns out comments in machine-to-machine communication are a bad idea.

I think the "calling BS" objection was to your categorical statement: "No computer-to-computer interchange format has comments," and not about whether they are a good idea or not (that is a separate argument).

How about ".comment" sections in ELF binaries, do they count?

https://wiki.osdev.org/ELF

Yes, comments tend to be turned over time into hints, directives, etc, etc, etc.

But that doesn't change the fact that people put comments into machine protocols.

For another example, lots of machine to machine protocols specify XML. Such as SOAP. They therefore all support comments.

In accord to the general trend, eventually they get abused into having a semantic meaning. For example https://support.ptc.com/help/windchill/wc111_hc/whc_en/index... shows how one system uses comments in SOAP to create documentation and a WSDL that lets interfaces to your code to be automatically generated.

And so comments eventually become executable. But that doesn't change the fact that comments can exist in machine to machine formats.

BTW, XML actually has what can be called "executable comments": processing instructions. They are very basic, but unlike plain comments they have two parts: target name and opaque instruction for the target. If one needs to use comments for some sinister purpose, at least processing instructions may be a better fit.