Small T$^{-1}_{1}$ peak near T$_{c}$ in unconventional BCS superconductors

It is usually believed that a coherence peak just below T$_{c}$ in the nuclear spin lattice relaxation rate T$_{1}^{-1}$ in superconducting materials is a signature of conventional s-wave pairing. We demonstrate that {\bf any} unconventional superconductor obeying BCS pure-case weak-coupling theory should show a small T$_{1}^{-1}$ coherence peak near T$_{c}$ ,generally with a height between 3 and 15 percent greater than the value at T$_{c}$. It is due to impurity scattering, magnetic effects, gap anisotropy and other effects that this peak has not been commonly observed.