The CHAOS alias in dig(1) works, but it is not
documented in current versions.
I woke up thinking maybe only the first two characters of the class are
checked and how much fun I could have with that, but that is not the case.
BIND's source tree at lib/dns/rcode.c supports CH and CHAOS, HS and HESIOD,
ANY, NONE, RESERVED0, and IN but not INTERNET.
-JP