  Recent work has shown that a self-correcting memory can exist in 3 spatial
dimensions, provided it is protected by a 1-form symmetry. Requiring that a
system's dynamics obey this type of symmetry is equivalent to enforcing a
macroscopic number of symmetry terms throughout the bulk. In this paper, we
show how to replace the explicit 1-form symmetry in the bulk with an emergent
1-form symmetry. Although the symmetry still has to be explicitly enforced on
the boundary, this only requires O(L^2) terms instead of O(L^3) terms. We then
reinterpret this boundary as a symmetry-protected topological defect in a bulk
topological order. Defects can have interesting memory properties even in the
absence of symmetry.
