---
abstract: 'Although several dozen double white dwarfs (DWDs) have been observed, for many the exact nature of the evolutionary channel(s) by which they form remains uncertain. The canonical explanation calls for the progenitor binary system to undergo two subsequent mass-transfer events, both of which are unstable and lead to a common envelope (CE). However, it has been shown that if both CE events obey the standard $\alpha_\mathrm{CE}$-prescription (parametrizing energy loss), it is not possible to reproduce all of the observed systems. The $\gamma$-prescription was proposed as an alternative to this description, instead parametrizing the fraction of angular momentum carried away in dynamical-timescale mass loss. In this paper, we analyze *simultaneous* energy and angular-momentum conservation, and show that the $\gamma$-prescription cannot adequately describe a CE event for an arbitrary binary, nor can the first phase of mass loss [*always*]{} be understood in general as a dynamical-timescale event. We consider in detail the first episode of mass transfer in binary systems with initially low companion masses, with a primary mass in the range 1.0–1.3$M_\odot$ and an initial mass ratio between the secondary and primary stars of 0.83–0.92. In these systems, the first episode of dramatic mass loss may be stable, non-conservative 