Hi Michelle,
While the rules do not explicitly enumerate whether print refers to an entire book or a specific paragraph or sentence, what it does say is that it is used when print uses both a short and a long dash.
It is my interpretation and understanding that use of the long dash only occurs when print uses both a short and a long dash in that particular instance (to show the distinction between both). The long dash in print is generally shown as a standard dash in braille. The braille reader just needs to know that when there are two dashes shown in print of differing sizes, there is a difference between the two. Hope this helps!