Given that the present work focuses on replication and mutation, it is relevant to consider what is the information contained in such a system. Classically, in biopolymers the units of the alphabet are, for example, nucleotides or amino acids. The information lays in the precise sequence of these entities within the biopolymer, which affects its physical properties, such as folding leading to (enzymatic) function. But what is the alphabet and the information in the assembly-based replicator systems analyzed here? There are two possible answers to this question.