Every app on every OS has a way to traverse/select and delete whole words to the right and to the left of the insertion point. E.g. InDesign/Story Editor/InCopy allow you to traverse[/select] words to the right by Cmd[+Shift]+Arrow Right and to the left – with Cmd[+Shift]+Arrow Left. InDesign and Story Editor also allow you to delete words to the right and words to the left with Cmd+Delete and Cmd+Backspace.
But, most unfortunately, and contrary to InDesign, Story Editor and all other apps on Earth, InCopy acts erratically when one tries Cmd+Backspace or Cmd+Delete: sometimes they delete a word to the left, but sometimes they delete a word to the right!
This is me hitting ONLY Cmd+Backspace:
This is me hitting ONLY Cmd+Delete:
I have checked CS5.5 and CC2018 (13.1) on OSX10.11. Is this a known bug? Am I missing something?
This does look like erratic behavior, it's worth trying to reset InCopy's preferences: InCopy Help | Customizing preferences and defaults
If that doesn't help, can you please submit a bug report here: Adobe InDesign Feedback
Thank you. I will submit a bug as this happens on a fresh installation too: latest InCopy, latest Windows 10. Resetting prefs doesn’t help.