Each local field $K$ has a unique label of the form "p.n.c.num", where

- p is the prime for the base $\mathbb{Q}_p$
- 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).