  We study a variety of questions related to entanglement in symmetry protected
phases, especially those introduced in arXiv:1106.4772 (Chen et al., 2011).
These phases are analogous to topological insulators in that they are short
range entangled states with symmetry protected edge or surface states. We show
that the now standard bulk-edge correspondence relating the entanglement
spectrum to the gapless edge spectrum holds for these phases as well. We also
consider the question of coupling these models to gauge fields or equivalently
of introducing long range entanglement. We argue that this procedure yields
models with perturbatively stable edge or surface states at a variety of
interface types. The non-onsite nature of the edge symmetry plays an important
role in our considerations.
