There was also a lot of work in this area in the 90s leading up to the y2k (non)event. Mostly back then it revolved around cobol, which was understandable given

There was also a lot of work in this area in the 90s leading up to the y2k (non)event. Mostly back then it revolved around cobol, which was understandable given y2k impact was in many cases related to legacy cobol systems. A lot of architecture visualization and recovering business requirements from code. I did some work on diagramming mainframe JCL files for example.