Attachments? Re: Indented multi-line strings (was: "Data blocks" syntax specification draft)

[Paul]

I have heard that attachments to messages are not allowed on this list,
which makes sense. However I notice that messages from Peter do have an
attachment, i.e., a signature.asc file.

I'm just curious; why and how do those particular attachments get through?
And should they get through, I guess? E.G., what if I attach a malicious
file labeled as .asc?

[Peter, I am not suggesting anything about you!  ;). ]

Paul C.