Each $p$-adic field $K$ has a unique label of the form "p.n.c.num", where
- p is the residue field characteristic,
- n is the degree of $K$ over $\mathbb{Q}_p$,
- c is the discriminant exponent of $K$,
- num is a positive integer giving the index of $K$ in a standard ordered list of those with the same triple (p,n,c).