  The colour-singlet axial-vector vertex plays a pivotal role in understanding
dynamical chiral symmetry breaking and numerous hadronic weak interactions, yet
scant model-independent information is available. We therefore use longitudinal
and transverse Ward-Green-Takahashi (WGT) identities, together with kinematic
constraints, in order to ameliorate this situation and expose novel features of
the axial vertex: amongst them, Ward-like identities for elements in the
transverse piece of the vertex, which complement and shed new light on
identities determined previously for components in its longitudinal part. Such
algebraic results are verified via solutions of the Bethe-Salpeter equation for
the axial vertex obtained using two materially different kernels for the
relevant Dyson-Schwinger equations. The solutions also provide insights that
suggest a practical Ansatz for the axial-vector vertex.
