rsb.h(3) on Linux
The text e2500e1399e6, as Debian 11 (Bullseye) shipped it.
rsb.h - The reference documentation of the librsb library comes in both HTML and Unix man pages formats. The following sections/man pages are available: The librsb library interface (rsb.h, rsb.F90) ; The Sparse BLAS interface to librsb (blas_sparse.h, rsb_blas_sparse.F90) ; Example programs and code.