A notecard, or “note,” is a plain text file used to provide information for numerous purposes.
To create your own notecard:
Once open, notecards that you can edit are shown with a white background. You can type and copy and paste text in a notecard, then click Save to save your changes.
You can add a full-permissions item to a notecard as an “embedded attachment” by dragging the item from your inventory onto the notecard, where it's shown along with its icon and name. (You cannot embed items that are not fully permissive.)
Notecards you can read but can't edit are shown with a dark background and Lock Lock.