Here is a short description of the application preferences.
Automatically launch ShelfMenu at login
If you check this box, ShelfMenu will be automatically started when you swith on your Mac.
Invoke ShelfMenu shortcut
This shortcut gives direct access to ShelfMenu using the keyboard. It is equivalent to clicking the application icon in the menu bar.
Add selection to Inbox
Send what is selected in the current application to Inbox.
Add clipboard to Inbox
Send the current content of the system clipboard to the Inbox. In other words, this sends the last item that you copied (either using the Edit / Copy command, or the ⌘-c shortcut) to the Inbox.
Add text note to Inbox:
Create a new text note and send it to the Inbox.
Open Organizer:
Open the Organizer window. This window allows you to re-organize your snippets: you can rename, move, and delete snippets (individually or by selecting multiple snippets).