  We analyze in detail the global symmetries of various (2+1)d quantum field
theories and couple them to classical background gauge fields. A proper
identification of the global symmetries allows us to consider all non-trivial
bundles of those background fields, thus finding more subtle observables. The
global symmetries exhibit interesting 't Hooft anomalies. These allow us to
constrain the IR behavior of the theories and provide powerful constraints on
conjectured dualities.
