  The capacity of the semideterministic discrete memoryless broadcast channel
(SD-BC) with partial message side-information (P-MSI) at the receivers is
established. In the setting without a common message, it is shown that P-MSI to
the stochastic receiver alone can increase capacity, whereas P-MSI to the
deterministic receiver can only increase capacity if also the stochastic
receiver has P-MSI. The latter holds only for the setting without a common
message: if the encoder also conveys a common message, then P-MSI to the
deterministic receiver alone can increase capacity.
  These capacity results are used to show that feedback from the stochastic
receiver can increase the capacity of the SD-BC without P-MSI and the sum-rate
capacity of the SD-BC with P-MSI at the deterministic receiver. The link
between P-MSI and feedback is a feedback code, which---roughly speaking---turns
feedback into P-MSI at the stochastic receiver and hence helps the stochastic
receiver mitigate experienced interference. For the case where the stochastic
receiver has full MSI (F-MSI) and can thus fully mitigate experienced
interference also in the absence of feedback, it is shown that feedback cannot
increase capacity.
