Chapter 10 in Chocolate War marks the beginning of the chocolate sales. Brother Leon makes a big show of putting up the posters in the cafeteria so everyone is held publicly accountable for their sales.
It is at this time that the Vigils become a bit aggravated that they are required to ensure the sale goes off without a hitch. However, Archie concludes in this chapter that it is a tribute to the Vigils' power that Brother Leon needs to vigils to help him. While the vigils have been fighting with the teachers and administration over who had the upper hand regarding their power for years, this year, the teachers are giving the vigils a legitimate claim to their influence and power.