  We consider the general abelian background configurations for the
Haldane-Rezayi quantum Hall state. We determine the stable configurations to be
the ones with the spontaneous flux of $(\Z+1/2) \phi_0$ with $\phi_0 = hc/e$.
This gives the physical mechanism by which the edge theory of the state becomes
identical to the one for the 331 state. It also provides a new experimental
consequence which can be tested in the enigmatic $\nu=5/2$ plateau in a single
layer system.
