Complex sentence: Salterford was "Saltreford" in 1086 and probably means "ford of the salters", where salter refers to a salt--dealer or carrier, rather than a maker of the commodity.
Split into simpler sentences: Salterford was "Saltreford" in 1086 and means "ford of the salters". J. Glover, A. Mawer & F. Stenton, "ibid" where salter refers to a salt--dealer or seller, rather than a maker of the commodity.