by Ajay Askoolum » October 16th, 2018, 3:05 pm
If you want APL to launch and open a file with extension W3, that is, use file association then reserved extensions are vital.
ZIP files have a pattern at the beginning of the file, they can be renamed to have any extension. However, unless that extension is zip, double clicking on it in File Explorer will not open and show the individual files within it, right-click on it will not show Extract All as an option.