  We streamline and generalize the recent progress in understanding
entanglement between spatial regions in Abelian gauge theories. We provide an
unambiguous and explicit prescription for calculating entanglement entropy in a
$\mathbb Z_N$ lattice gauge theory. The main idea is that the lattice should be
split into two disjoint regions of links separated by a buffer zone of
plaquettes. We show that the previous calculations of the entanglement entropy
can be realized as special cases of our setup, and we argue that the
ambiguities reported in the previous work can be understood as basis choices
for gauge-invariant operators living in the buffer zone. The proposed procedure
applies to Abelian theories with matter and with continuous symmetry groups,
both on the lattice and in the continuum.
