What does format A in ~ A mean?

Question

With format you can use, among other things, ~S and ~A

While S in ~S for S-expression , what does A in ~A mean? Apparently, he comes out without escape, but I was wondering what the letter really means ...?

Answer 1

It means aesthetics. A formatted output is not shielded. See http://www.lispworks.com/documentation/HyperSpec/Body/22_cda.htm

By the way, S stands for standard, not S-expression.