What is the punctuation mark called for titles?

There isn't a specific punctuation mark exclusively for titles. The punctuation used for titles depends on the type of title and the context. Here are some common examples:

Books: *Italicized*

Articles: "Quotation marks"

Movies: *Italicized*

Songs: "Quotation marks"

Plays: *Italicized*

Chapters in a book: "Quotation marks"

It's important to remember that these are general guidelines and specific publications or style guides may have their own rules.