In dynamic heterogeneous environments, such as Pervasive Computing, context-aware adaptation is a key concept to meet the varying requirements of different clients. To enable such functionality, context information must be gathered and eventually presented to the application performing the adaptation. Therefore, a common representation format for the context information is required. This paper introduces a novel representation language for context information: Comprehensive Structured Context Profiles (CSCP). CSCP is based on the Resource Description Framework (RDF) and is designed to be comprehensive and thoroughly structured to describe the entire context of mobile sessions. Besides the design of CSCP, the paper describes our experiences with CSCP in a running system, a Mobility Portal for context-aware adaptive access to email and Web information services.