  We consider a higher gauge topological model in three spatial dimensions
whose input datum is a 2-group encoding the mixing of a 0-form $\mathbb Z_2$-
and 1-form $\mathbb Z_3$-symmetry. We study the excitation content of the
theory on the symmetry-preserving boundary. We show that boundary operators are
organised into the fusion 2-category of 2-representations of the 2-group. These
can be interpreted as categorical charges for an effective boundary model that
inherits a global 2-group symmetry from the bulk topological order.
Interestingly, we find that certain simple 2-representations are physically
interpreted as composites of intrinsic excitations and condensation defects.
