Outliner or Outline Processor
https://en.wikipedia.org/wiki/Outliner
An outliner (or outline processor) is a specialized type of text editor (word processor) used to create and edit outlines, which are text files which have a tree structure, for organization. Textual information is contained in discrete sections called "nodes", which are arranged according to their topic–subtopic (parent–child) relationships, sort of like the members of a family tree. When loaded into an outliner, an outline may be collapsed or expanded to display as few or as many levels as desired.
Info
- Frank Baldwin to Me (Direct Message) (1:29 PM)
https://www.youtube.com/watch?v=KoddCmn3eL0