  In this paper we re-examine the geometric interpretation of gluing conditions
in WZW models and the possible D-brane configurations that they give rise to.
We show how the boundary conditions are encoded in the gluing conditions
imposed on the chiral currents. We analyse two special classes of gluing
conditions: the first, which preserves the affine symmetry of the bulk theory,
describes D-branes whose worldvolumes are given by `twisted' conjugacy classes;
the second class describes configurations which include subgroups and cosets.
