“…Periodic patterns. An important purpose of this paper is to emphasize that coclass graphs G(p, r) are particularly well suited for visualizing periodic properties [30,33] of infinite sequences of finite p-groups G, such as parametrized power-commutator presentations [15,66], automorphism groups Aut(G), Schur multipliers H 2 (G, Z p ) and other cohomology groups of G, transfer kernel types κ(G) [59], transfer target types τ (G) [60], and defect of commutativity k(G) expressed by the depth dp(G) (Corollaries 3.1.1 and 3.10.1). In number theoretic applications, selection rules for second p-class groups G = G 2 p (K) of special base fields K [58] are additional periodic properties.…”