Notations are inherited - an image gets notations from its folder, the folder inherits notations from its parent folder, which then inherits notations from its parent folder and so on, up to the very top to the Shared Notations.
When a folder inherits notations and also has its own notations, notations are added together. It is possible to break the inheritance, in this case inherited notations are not used.
This way you can have notations which are available for all images on your computer (Shared Notations), you can reuse notations by placing them higher in the folder tree, and you can customize notations for each specific folder to suit different applications or clients.
To edit Shared Notations, choose Shared Notations from the Tools menu. See the previous topic Creating sets of notations for the instructions of how to edit notations.
See related topics:
§Assigning notations to images