Apple Aperture 2 - Manual (Page 272)

272 Part II Photo Editing
To show the Metadata pane of the Inspector HUD:
m Choose Window > Show Inspector HUD (or press H), then click Metadata.
You can also add the actual metadata you want applied to your images to the fields of
a metadata view and save it as a metadata preset. You can then use that metadata
preset to apply combinations of metadata to images as you import them or change
them using the Batch Change dialog. For example, if you have a specific combination
of metadata that one of your services always requires, you can create a metadata
preset just for that service. Then whenever you import images destined for that service
or prepare images to send to that service, you can apply the metadata you need using
the preset you created.
You can create and manage your own metadata views and metadata presets using the
Metadata Action pop-up menu in the Metadata inspector.