Invariant subspaces for the backward shift on Hilbert spaces of analytic functions with regular norm.
It is shown that under certain regularity conditions on the norm, the functions in a nontrivial invariant subspace of the backward shift operator have meromorphic pseudocontinuations in the Nevanlinna class of the exterior of the unit disk. In addition, we provide a regularity condition which implies that the subspace itself is contained in the Nevanlinna class of the disc.