THE DEDICATION. Buffyverse Term/Concept/Idea/Intratext.
A ritual, completed in "Bad Girls," in which The Mayor becomes invincible 100 days prior to his Ascension. (In "Bad Girls" The Mayor displays a Things-to-Do list that includes "Greet Scouts, Lumber Union Reschedule, Call Temp Agency, Become Invincible, Meeting With PTA, Haircut.")
The Mayor tests his new invulnerability by allowing the vampire Vincent to cleave his head in two with a sword. In subsequent episodes, he withstands a letter opener impaled in his hand (by Angel in "Enemies") and a sword stuck into his chest (by Giles in "Graduation Day," Part I).