In the SHOPPER. project, we are building a classification of structural assumptions and information resources present in domains such as grocery stores, libraries, office buildings - almost anything for public use. Assumptions based on structured domains can serve as cues, or appropriateness conditions (Converse and Hammond 1992) for execution of plans. For example, knowing that signs in an aisle indicate the type of objects there, we can suspend a goal (Hammond et al. 1990) of obtaining chicken soup by indexing according to type "soup". When a sign saying "soup" or another soup is seen, the opportunity is recognized to achieve the goal of obtaining the particular soup desired.