“…The fact that a Geniza merchant preferred to charter a single design of dual‐capability vessel (sea‐to‐river) explains the rare mention of riverboats in these records. By contrast, the Digest and Islamic judicial and historical references qualified ships into different categories (Scott, 1932, 4: 202, Digest XIV, 1, 1, 12; Minhāj?, 1955, 1: 94–6, 293–4; Ṫaḣāw?, 1972, 1: 266–7; Qarāf?, 1994, 10: 355; Dujayl?, 1912–13: 93–106, 198–205, 393–402; Stern, 1962: 175–6; Zayyāt, 1949: 321–64; Barrāw?, 1948: 282; c Abd al‐Fattāḣ, 1986: 160) 16…”