In literature the word single is deployed with a range of meanings that underscore themes of uniqueness, isolation, or emphasis on one element among many. It can denote exclusivity or the sole instance of something, as when a character is described as the "single gentleman" to mark his distinctiveness [1] or when a solitary candle lends an atmosphere of intimate focus [2]. At times it functions quantitatively, specifying a unique measure or unit—as in references to a single scudo of salario [3] or a single thread both in literal description and technical measurement [4, 5]. Whether enhancing individuality by contrasting the solitary against the collective, or stressing the importance of a lone detail—like the single diamond shining brighter than the sun [6]—its use encourages readers to pay close attention to what would otherwise be overlooked.