The Note allows you to write a note that can be left inside a crate or other storage for other people to read. It requires Thatch and Fiber to create.
The text menu disappears quickly, so you should write very fast! Alternatively, you can type the note ahead of time in a text editor and copy paste it into the note in-game. Keep in mind the notes have a maximum character count of 200, including line-breaks.
Since the resources needed for this item are common, it can be crafted in large quantities to gain minuscule amounts of XP.
The Note is also used to make custom recipes in the Cooking Pot by adding the ingredients in, exiting inventory, and hold E to select the "Make Recipe" option.
There is no indication of when the 200 character count is reached, so it may be a good idea to write your message in an external word processor that can show character count.