  Mixed codes, which are error-correcting codes in the Cartesian product of
different-sized spaces, model degrading storage systems well. While such codes
have previously been studied for their algebraic properties (e.g., existence of
perfect codes) or in the case of unbounded alphabet sizes, we focus on the case
of finite alphabets, and generalize the Gilbert-Varshamov, sphere-packing,
Elias-Bassalygo, and first linear programming bounds to that setting. In the
latter case, our proof is also the first for the non-symmetric mono-alphabetic
$q$-ary case using Navon and Samorodnitsky's Fourier-analytic approach.
