Each L-function has a label of the form d-N-q.k-x-y-i, where
- is the degree of .
- is the conductor of . When is a perfect power we write as e, since can be very large for some imprimitive L-functions.
- q.k is the label of the primitive Dirichlet character from which the central character is induced.
- x-y is the spectral label encoding the and in the analytically normalized functional equation.
- i is a non-negative integer disambiguating between L-functions that would otherwise have the same label.