Permanently delete OR Remove calendar entry - how to set default

I did this once before but I’ve forgotten how.

From Calendar view or inside a Meeting document, when clicking Action > Cancel, a dialog box pops up with two options :

Permanently delete… or

Remove …

The default now is Remove. I want to make it permanent. Can anyone tell me how I set this parameter - I think it’s when calling (OptionDlg) subform?

Thanks a lot.