  Recently, Moriya et al. (2013) developed an analytic bolometric light curve
model for supernovae interacting with dense circumstellar media. Because of the
dense circumstellar medium, the shocked region is assumed to be radiative and
make a thin dense shell. The model is based on the conservation of momentum in
the shocked dense shell. However, the analytic model was mentioned to neglect
the 'snow-plow' phase of the shocked dense shell by Ofek et al. (2014). The
'snow-plow' or momentum-conserving phase refers to the period in which the
momentum injection from the supernova ejecta is almost terminated and the
radiative shocked dense shell keeps moving due only to the momentum previously
provided by the supernova ejecta. In this Note, I clarify that the analytic
model of Moriya et al. (2013) does take the 'snow-plow' phase into account and
the criticism of Ofek et al. (2014) is incorrect. In addition, Ofek et al.
(2014) related the sudden luminosity break observed in the light curve of Type
IIn SN 2010jl to the transition to the 'snow-plow' phase. However, I argue that
the sudden transition to the 'snow-plow' phase is not consistent with the
luminosity break observed in SN 2010jl. The luminosity break is likely to be
related to other phenomena like the dense shell exiting the dense part of the
circumstellar medium.
