Book excerpt: Part 1: Theories of Information Sharing. -- Information sharing in context. -- Patterns of sharing - enablers and barriers. -- Social navigation. -- Part II: Two Practices in Information Sharing. -- Introducing the two cases. -- Claims handlers. -- Expert organisation. -- Part III: Insights into Information, Knowledge Sharing and Social Capital. -- Dimensions of social capital in the two cases. -- Social capital and sharing - building structures for knowledge sharing and its management. -- Importance of the awareness of social capital in connection with information and knowledge sharing in today's companies. -- Appendices: (1) interview protocol: dimensions of social capital and knowledge sharing; (2) questionnaire: group identity aspects. -- References. -- Index.