  The aim of this letter is to discuss the virtual identity of two recent tidal
theories: the creep tide theory of Ferraz-Mello (Cel. Mech. Dyn. Astron. 116,
109, 2013) and the Maxwell model developed by Correia et al. (Astron.
Astrophys. 571, A50, 2014). It includes the discussion of the basic equations
of the theories, which, in both cases, include an elastic and an anelastic
component, and shows that the basic equations of the two theories are
equivalent and differ by only a numerical factor in the anelastic tide. It also
includes a discussion of the lags: the lag of the full tide (geodetic),
dominated by the elastic component, and the phase of the anelastic tide. In
rotating rocky bodies not trapped in a spin-orbit resonance (e.g., the Earth)
the geodetic lag is close to zero and the phase of the semi-diurnal argument in
the anelastic tide is close to 90 degrees. The results obtained from combining
tidal solutions from satellite tracking data and from Topex/Poseidon satellite
altimeter data, by Ray et al., are extended to determine the phase of the
semi-diurnal argument in the Earth's anelastic tide as sigma_0=89.80 \pm 0.05
degrees.
