preliteral
/ˈprɛlɪtərəl/Definitions
1. adjective
relating to or denoting the part of a written work that is introductory or preliminary.
“The preliteral section of the novel set the tone for the rest of the story.”
2. noun
a preliminary or introductory part of a written work.
“The preliteral passage in the book provided background information on the characters.”