To address problems related to use and formation of tables of contents, the present inventors, devised among other things, an exemplary table-of-contents (TOC) data structure and related systems and methods. One exemplary method entails associating a node from one TOC with a node of another TOC and then assigning a unique identifier to the associated pair of nodes. The unique identifier can then be used to logically define another TOC that includes portions of the two original TOCs. Another exemplary method entails tagging or associating nodes of a TOC with one or more view labels. (Identifiers for node relationships rather than the nodes themselves are tagged with the labels in some embodiments.)