  An (m, n)-string bound state (with m, n relatively prime integers) in type
IIB string theory can be interpreted from the D-string worldsheet point of view
as n D-strings carrying m units of quantized electric flux or quantized
electric field. We argue, from the D-brane worldvolume point of view, that
similar Dp-brane bound states should also exist for $2 \le p \le 8$ in both
type IIA (when $p$ is even) and type IIB (when $p$ is odd) string theories. As
in $p = 1$ case, these bound states can each be interpreted as $n$ Dp-branes
carrying m units of quantized constant electric field. In particular, they all
preserve one half of the spacetime supersymmetries.
