Peregrination describes the period of time avout spend Extramuros between the auts of Voco and Inbrase. Fraa Erasmas endures an unexpected Peregrination when so many avout are Evoked to deal with the Advent that the Saecular Powers are unable to provide transportation for all.
Prior to the action of the novel Anathem, the entire Mathic World endured a period of Peregrination following the Third Sack that destroyed all but the Three Inviolates. During Peregrination, avout are expected to keep the spirit, if not the exact letter, of the Discipline.