2.3.2. - Doc Strings
Everything between pairs of triple double quotes
"@" is a doc string
comment.
The comment block can span lines, but not files.
Unlike
comments that begin with a pound sign
#, doc string comments will
not be saved with a macro when included as part of the macro definition
in the source file.
Thus, doc string comments can be interspersed in macro code without
putting any extra burden on the input preprocessor as it does macro substitution.