  We propose when and why symmetry enhancements happen in massless
renormalization group (RG) flows to two-dimensional rational conformal field
theories (RCFTs). We test our proposal against known RG flows from unitary
minimal models. We also suggest which sign of the relevant coupling triggers
the massless RG flow. The other sign triggers massive RG flows to topological
quantum field theories (TQFTs). We comment on their ground state degeneracies.
