  We discuss the conclusions on the symmetry of hidden order (HO) in URu2Si2
that may be drawn from recent torque experiments in rotating magnetic field by
Okazaki et al. [1]. They are very sensitive to changes in the magnetic
susceptibility induced by HO. We show that the observed twofold angular torque
oscillations give evidence that hidden order has degenerate E- type (yz,zx)
symmetry where both components are realised. The oscillations have the wrong
characteristics or are absent for the 1D nontrivial representations like
quadrupolar B1 (x^2-y^2) and B2 (xy) type HO or hexadecapolar A2(xy(x^2-y^2))
type HO. Therefore they may be excluded as candidates for hidden order. We also
predict the field-angular variation of possible field-induced Bragg peaks based
on underlying E-type order parameter and discuss the expected elastic constant
anomalies.
