  The recent reported charmed-strange resonance at 2.32 GeV/c suggests a
possible multiquark state. Three types of multiquark bound states are reviewed.
A previous model-independent variational approach considers a tetraquark with
two heavy antiquarks and two light quarks as a heavy antidiquark with the color
field of a quark bound to the two light quarks with a wave function like that
of a heavy baryon. Results indicate that a charmed-strange tetraquark $\bar c
\bar s u d$ or a bottom-strange tetraquark $\bar b \bar s u d$ with this
"diquark-heavy-baryion" wave function is not bound, in contrast to
"molecular-type" $D-K$ and $B-K$ wave functions. However, a charmed-bottom
tetraquark $\bar c \bar b u d$ might be bound with a very narrow weak decay
mode. A "molecular-type" $D-B$ state can have an interesting $B_c \pi$ decay
with a high energy pion,
