One of the four large banks in my country I worked at only a few years ago still managed all their internal change management process on a fairly old IBM mainfr

One of the four large banks in my country I worked at only a few years ago still managed all their internal change management process on a fairly old IBM mainframe. You had to connect via an arcane telnet client (tn3270 protocol perhaps?) and input the change details. No fancy web forms. Perhaps it was a limitation of the application, but you couldn't mix uppercase and lowercase in the one form.