Have you tried filling out an IRS form directly? What a nightmare. This page shows IRS form references via a directed graph. Nodes represent IRS documents (forms and schedules), and edges represent references. There are a number of reasons two documents might be joined by an edge. In most cases, an edge from Document X to Document Y indicates that Document X is dependent on a line from Document Y (e.g. "Enter the amount of all taxes from Schedule A (Form 1040 or 1040-SR), line 7"). In other cases, an edge indicates that Document Y should be filed instead of (or in addition to) Document X.

The graph was generated by scraping document instructions from the IRS website, and parsing them for references to other documents.

Take a look at the code on GitHub.