The aim of this chapter is to present a formal theory of the structure of information that will support a variety of statements about documents in various media, their internal structure, and how they function in the world at large. We begin by sketching an approach to anchoring symbolic systems in human cognition and discuss various levels of intentionality that occur. We then consider compositionality in different symbolic systems and the sometimes complex coreference relations that arise from that. This theory is the basis of a program for translating natural language into logical form, and this is described. Then the theory is applied to the specific case of diagrams as information-bearing objects, and a logical theory of Gantt charts is constructed as an illustration. Finally there is a discussion of issues raised with respect to various modalities and various manifestations of symbolic artifacts.