I present a classification of random Dirac fermions in 2d based on discrete symmetries. This classification is slightly finer than the
Altland-Zirnbauer classification of hermitian matrices and leads to thirteen classes. Upon disorder averaging each of these classes can be formulated as a current-current perturbation of a Lie super-current algebra. An all-orders beta-function is proposed for general current-current perturbations. The example of anisotropic su(2) is presented. We then study the RG flows for the Chalker-Coddington network model and the network model for the spin quantum Hall transition. Coset conformal field theories are discussed as possible fixed points.
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