TMF divisibility conjecture for rational vertex operator algebras

Let $V$ be a rational vertex operator algebra with central charge $c=24n$, where $n$ is an integer, and suppose that $V$ has only one irreducible module. Let the character of $V$ be a power series in the modular parameter, and call its coefficient independent of that parameter the constant term. TMF divisibility conjecture. The constant term in the character is divisible by

$$\frac{24}{\operatorname{gcd}(24,2n)}.$$

This is the mathematical specialization to bosonic holomorphic conformal field theories of the divisibility constraint arising from the conjectural relation between TMF and two-dimensional $(0,1)$ supersymmetric quantum field theories. The source presents it as a conjectured constraint; its general validity remains open.