The search for possible effects of parity violations in the electromagnetic sector has achieved great accuracy with the latest cosmic microwave background (CMB) observations. The sensitivity of current and future experiments is such that the need to understand the interaction of parity violations with several competing effects is now crucial in order to improve current constraining power. It also allows to not only put constraints on the most generic features of parity violations but also for distinguishing between several production mechanisms, if any effect is ever observed. The results here reported were presented at the Cosmic Polarization Rotation workshop held in Florence on 7–8 September 2015.