At the end of "Notes on Chapter 1" in the Preface to the Third Edition of *Sphere packings, lattices and groups*, Conway and Sloane write the following: > Finally, we cannot resist calling attention to the remark of Frenkel, Lepowsky and Meurman, that **vertex operator algebras** (or conformal field theories) are to lattices as lattices are to codes. I would like to understand better what the precise analogy is that is being made here. Through my attempts to read Frenkel, Lepowsky and Meurman's book, I am aware of the story about how the "exceptional" objects, Golay code ---> Leech lattice ---> Moonshine module, form a hierarchy with increasingly large symmetry groups, Mathieu group *M*<sub>24</sub> ---> Conway group *Co*<sub>1</sub> ---> Monster group, and how this hierarchy led to the conjecture that uniqueness results for the Golay code and Leech lattice carry over to a uniqueness property of the Moonshine module. Frenkel, Lepowsky and Meurman speak of many analogies between the theories of codes, lattices, and vertex operator algebras. I have some understanding of the connections between codes and lattices, but so far very little understanding of vertex operator algebras and of their connection with lattices (despite having a bit of relevant physics background in conformal field theory). My questions are 1. Are the parallels alluded to above a peculiar feature of these exceptional structures, or something that holds more generally? 2. Is there a "baby example" one can look at of these correspondences - something based on smaller and more elementary objects?