  The existence of cusps on non-periodic strings ending on D-branes is
demonstrated and the conditions, for which such cusps are generic, are derived.
The dynamics of F-, D-string and FD-string junctions are investigated. It is
shown that pairs of FD-string junctions, such as would form after
intercommutations of F- and D-strings, generically contain cusps. This new
feature of cosmic superstrings opens up the possibility of extra channels of
energy loss from a string network. The phenomenology of cusps on such cosmic
superstring networks is compared to that of cusps formed on networks of their
field theory analogues, the standard cosmic strings.
