I have seen sparse matrix-matrix multiplication commonly referred to as SpGEMM, which means general/generalised sparse matrix-matrix multiplication. I've seen it once or twice (forgot where) as SpMM.
My question is, what is "general" referring to? The type of sparse matrix? Does there exist a non-general sparse matrix-matrix multiplication algorithm? All the routines/kernels I've come across are designed for sparse matrices which doesn't assume a structure, so isn't the word "general" a bit redundant? SpMM seems like a more fitting acronym.