It is punctuation too, and we use even more signs. But we have newer forms, specially for calling for attention. The delimiters are of course . But the empty spaces between words, paragraphs and chapters are the most powerful delimiter. All the graphical means used to label those paratexts are new delimiters.
Jokers are signs with unpredictable meaning.
Three dots or an apostrophe mark an exclusion. In my paper I discuss several cases of overlapping and double function of signs, especially new signs used in desk top publishing.