There is a reference in User Manual v1.2.1 to auto-completion. But how to use it? I found no menu entry for that and I don't find the var list, too.
I found the auto-completion on my own:
1. Be sure to have your file opened in COBOL-Editor.
2. Press +
If one wants to see the definition of a variable one has to place the cursor at its end and do +.