Rotation profiles developed between concentric, co-rotating cylinders. The axes are the rotation speeds of the cylinders defined by a Reynolds number Re_1,2 = Ω_1,2r_1,2(r₂ − r₁)/ν, where 1 (2) refers to the inner (outer) cylinder. The cylinder radius is r and Ω is the angular velocity. The kinematic viscosity is ν. The flow profiles are classified by a local exponent of angular velocity q ≡ − ∂lnΩ/∂lnr. In cyclonic flow q < 0. The anti-cyclonic regime is further divided in to quasi-Keplerian and centrifugally unstable flows, the boundary between the two is the flat angular momentum profile, q = 2.