While there seems to be a general agreement that HTSCs are d-wave, I have heard from a few places that there is still a debate as to whether HTSCs are actually a mixture of s-wave and d-wave models. Is this true? Also, what is meant by s-wave? Is the s-wave model the BCS model (with the s referring to the shape of the Fermi surface that the model deals with)? And if HTSCs are a combination of s-wave and d-wave, how do the two different models interact with each other? Is one model good at explaining SC behavior from Tc to T* while the other is good from T* to T = 0K? Do they work in tandem but differ across different fields?