EN is missing a means of representing direct 1:1 or many:1 network relationships across notes. These could be causal chains or vectors on any kind of direct linear relationship. Folders supports the coarse clustering of notes by topic. Tagging supports the intra- and inter-folder clustering of notes by more atomic categories. What is missing is a way to represent direct linear relationships between notes. Note #1 is directly linked to Note #2. Note #2 is directly linked to Note #3. Thus through inheritance, Note #1 is indirectly linked to Note #3. Allowing this kind of relationship modeling would allow EN users to create network models in addition to tag clouds. There are a number of use cases that follow from this: * Any serial ordering of notes - such as research paper chapter outlines: Chapter 1, Chapter 2, Chapter 3... * Content notes' direct many-to-one relationship to source citation notes (needed by academics) * Social network analyses, including Person A works at Company 1; Person B (also) works at company 1; Person A is directly related to Person B; Person A is indirectly related to Person C.... This social effect results in this other social effect. Reminder to <take some action> A about <some goal> #2. ... and many more. The UI has two parts, one easy, one hard. Creating Relationships: This could be relatively easy, with a drag and drop method. Dragging Note 1 over to Note 2 creates a network vector in the direction of 1 -> 2. Visual Display of Network Relationships: This would be harder but still there are many good examples of this in the visual display of social network nodes and spokes. The user could right-mouse click/CMD-menu to make the selected note the central/core/hub node and display first, second, and third order "satellite" nodes as bubbles around the central node. When the user mouse clicks on a satellite node, it becomes the central node/hub and all the note bubbles reorient around the new central axis. (I offer one very basic example of what could be a much cleaner graphical display befitting EN). The overall amount of information that could be usably displayed would be limited - especially on phones -- but filtering by tag and limiting to one notebook would be easy constraints here. Further, users would just have to learn to be judicious in using this feature.