How do graphic artists keep image notes? Is there any way to add notes in Photoshop? (see details)

How do artists keep the design notes when working on images?
Can Photoshop itself allow notes that:

1. Cannot be seen on the image and does not print out on the image.
2. Can be read when the file is open.
3. Is removed when the file is saved as a jpeg and cannot be read or retrieved in jpeg.

Thanks for any input. Right now I keep a desktop notebook which is not efficient at all.