  We analyze symmetries and magnetic properties of Cooper pairs appearing as
subdominant pairing correlations in inhomogeneous superconductors, on the basis
of the quasiclassical Green-function theory. The frequency symmetry, parity,
and the type of magnetic response of such subdominant correlations are opposite
to those of the dominant pairing correlations in the bulk state. Our conclusion
is valid even when we generalize the theory of superconductivity to recently
proposed diamagnetic odd-frequency superconductors. As a consequence, Cooper
pairs are classified into eight classes in terms of their symmetries and
magnetic properties. Anomalous magnetic properties of subdominant components
can be probed by studying the Meissner effect.
