From the PDF introduction
A Web Enhancement for Cityscape
Even as a city can present different adventuring challenges than other environments, so do heroes with unusual abilities rise to meet those challenges. In a campaign that covers multiple settings, it hardly matters if some characters are more effective in one, and others in another; in fact, such myriad skills are all but essential. In a city-focused campaign, however, a traditional druid or ranger might find her abilities less useful than those of classes such as the rogue or the bard.
Of course, you can gear these classes toward adventuring in the city from the start. The urban barbarian is no wild warrior from a distant land, but a rage-driven streetfighter from the worst neighborhoods. The urban druid still seeks to manipulate the natural world while revering its powers, but she may be more interested in the ebb and flow of the city -- and the living things within -- than in the surrounding woods or distant fields.
Presented here are urban-oriented alternate class features for the barbarian, druid, ranger, scout (Complete Adventurer), and spirit shaman (Complete Divine) classes. Not all city-dwelling members of these classes possess these features, but the options exist for those who want them. In addition, while the paladin is hardly a wilderness-oriented class, her summoned mount is not appropriate for all city-focused campaigns, so she gains a few alternate class features as well.
Several class features presented here reference feats and mechanics found in Cityscape.