What is a window control
(Sorry, I didn't mean to confuse the issue with "window control". That phrase was just to differentiate "control" from "GUI control".)
Thanks for the reply Hugo
The Help file is not intended as a dictionary of programming vocabulary. You may notice the acronym "GUI" is never defined under the GUI command either. I think few languages' documentation will explicitly define generic terminology like Boolean, binary, string, subroutine, etc. etc.; otherwise, every language would have enormous, redundant documentation. The term control (also called a widget) is applicable to any language with GUI capability.
I read ALL the control commands. None of them comes right out and says what a control is. I find that to be a major shortcoming of the documentation. While it is extensive, it fails to provide succinct definitions.