Here's the protocol for my local board:
Officials are expected to confirm their games. Email addresses for athletic directors, faculty managers, or site directors, as well as partners, are on the Arbiter website. The email should state the gender, level, site, day, date, and time of the game, along with one’s contact information, sent to both the school, and to one’s partner. A confirmation, emailed in this manner, looks professional, and assures everyone that the officials have been properly assigned for the game.