  Recently, an analysis of all available planar oxygen shift and relaxation
data for the cuprate high-temperature superconductors showed that the data can
be understood with a simple spin susceptibility from a metallic density of
states common to all cuprates. It carries a doping dependent but temperature
independent pseudogap at the Fermi surface, which causes the deviations from
normal metallic behavior, also in the specific heat. Here, a more coherent,
unbiased assessment of all data, including planar Cu, is presented and
consequences are discussed, since the planar Cu data were collected and
analyzed prior to the O data. The main finding is that the planar Cu shifts for
one direction of the external magnetic field largely follow from the same
states and pseudogap. This explains the shift suppression stated more recently,
which leads to the failure of the Korringa relation in contrast to an
enhancement of the relaxation due to antiferromagnetic spin fluctuations
originally proposed. However, there is still the need for a second spin
component that appears to be associated with the Cu $3d(x^2-y^2)$ hole to
explain the complex Cu shift anisotropy and family dependence. Furthermore, it
is argued that the planar Cu relaxation which was reported recently to be
rather ubiquitous for the cuprates, must be related to this universal density
of states and the second spin component, while not being affected by the simple
pseudogap. Thus, while this universal metallic density of states with a
pseudogap is also found in the planar Cu data, there is still need for a more
elaborate scenario that eludes planar O.
