The label of a Belyi map $\phi$ has the form $d$T$G$-$\lambda_0\_\lambda_1\_\lambda_\infty$-m encoding the following data.

  • $d$T$G$ is the transitive group label of the monodromy group of $\phi$. Here $d$ is the degree of $\phi$.

  • $\lambda_i$ are partitions of $d$ specifying the ramification type of $\phi$, each written using . as a separator between the parts of the partition.

  • m is the Galois orbit label, a non-negative integer written in base 26 using the 26 symbols a, b, ..., z.