5d superconformal field theories can be defined as 11d M-theory on canonical threefold singularities, which are generally non-isolated. In particular, the crepant resolution of the singularity encodes a lot of physical information. I will try to capture the flop invariant information of the resolution geometry with a diagram, which has important physical applications.

References: 1907.05404, 1912.04264, 2004.15007.