Alley may be paved, or unpaved, and a blind alley is a cul-de-sac. Modern urban developments may also provide a service road to allow for waste collection, or rear access for fire engines and parking. Because of geography, steps (stairs) are the predominant form of alley in hilly cities and towns. This includes Quebec City in Canada and in the United States Pittsburgh (see Steps of Pittsburgh), Cincinnati (see Steps of Cincinnati), Minneapolis, Seattle, and San Francisco as well as Hong Kong, Genoa and Rome. Some alleys are roofed because they are within buildings, such as the traboules of Lyon, or
Phrase book books designed for merchants involved in the international trade are attested as well. The earliest known example of this genre is a 1424 manuscript compiled by one Master George of Nuremberg, and intended to help Italian merchants to use High German. Printed phrase books appeared by the late 15th century, exemplified by the "Good Boke to Lerne to Speke French" (ca. 1493-1496). In Asia, phrase books were compiled for the travelers on the Silk Road already in the first millennium AD, such as a Dunhuang manuscript (Pelliot chinois 5538) containing a set of useful Saka ("Khotanese") and Sanskrit phrases. James