A list of state codes must name at least one of the 16 known codes and nothing
else (each entry trimmed and compared case-insensitively; blank entries are
skipped), so a typo never becomes a silently-dropped filter that returns the full
nationwide set. normalizeStates returns the canonical form.
A list of state codes must name at least one of the 16 known codes and nothing else (each entry trimmed and compared case-insensitively; blank entries are skipped), so a typo never becomes a silently-dropped filter that returns the full nationwide set.
normalizeStatesreturns the canonical form.