Similarly, defining a normal distribution of iteromers in absence of iteroselectivity implies arbitrary decisions. We propose to define the normal distribution of iteromers as the distribution obtained after complete consumption of the limiting reactant(s) for iterative irreversible reactions with identical kinetic constants (see details in the Supporting Information). The evolution of the concentration of iteromers under this definition is illustrated in Figure for a tetra-functional substrate. These arbitrary choices ensure that the normal distributions are relatively simple to calculate, invariant to changes in concentration, and that complete per-functionalization results from an excess of reagent to the number of functional groups on the substrate. Yet, we are conscious that these choices lead to a poor description of a normal distribution of iteromers in reversible reactions at equilibrium. Further considerations are discussed in the Supporting Information including formulas to calculate the normal distributions and precalculated tables for convenience. Rebek Jr and co-workers previously described the normal distribution in a similar fashion to evaluate the iteroselectivity of a reaction over time despite not using the terminology and definitions introduced herein. Figure . Evolution of the concentration of iteromers for an iterative reaction in absence of iteroselectivity (i.e. same kinetics for each iteration) on a tetra-functional substrate A reacting with B. The graph corresponds to an iterative reaction with first order kinetics in each iteromer. The starting concentration of A and the kinetic constant are arbitrarily set to 1 M and 1 s -1 , respectively. The initial stoichiometry of A and B is the only parameter that determines the normal distribution of iteromers after complete consumption of the limiting reactant. Red dashed lines show the normal distribution of iteromers upon complete consumption of B as limiting reactant (1, 2, or 3 equivalents). Formulas to calculate the concentration evolution and normal distributions are detailed in the Supporting Information, followed by precalculated tables of normal distributions for convenience.