.NWCP File Extension
What is an NWCP file?
Document used by Nisus Writer Pro, a rich text word processor; temporarily contains text and images that you add via "Copy" or "Cut;" referenced when you select "Paste."
You can create, edit, and delete NWCP files by selecting Nisus Writer Pro → Preferences..., and then select "Clipboard" icon. Here, you'll be able to create a new clipboard, edit the contents of a clipboard, delete a clipboard, and activate a specific clipboard.