Each noise profile can be annotated with the camera settings and other conditions under which it was created. Annotations serve multiple purposes. First, they provide an "audit trail" indicating the conditions under which a profile was created, so that individual users can determine whether a particular profile is a good fit for their particular shooting preferences. Second, they are used by the automatic profile loader to automatically find the "best" profile for a given image.
The Annotations page contains more than a dozen fields that you can use to annotate profiles. The Manufacturer and Model fields should always be filled in if possible. (For film scanners, the Film field should also be filled in.) These fields are mandatory for use with the automatic profile loader and the automatic profile directory creation feature. Whenever possible, these fields should exactly match the corresponding fields in the EXIF data for images from the same camera. For instance, the EXIF data in a Minolta A2 reports the Maker to be "Konica Minolta Camera, Inc." (note the comma and period), and the Model is "DiMAGE A2". The automatic profile loader ignores whitespace, but other characters are matched exactly, so it is important to fill these fields in accurately. The "Auto Fill" button (see below) is especially useful for this. You can also use the EXIF Viewer tool in Noise Ninja to examine EXIF data in an image.
Note: Some cameras report different Model values in different regions of the world. In you are using an Asian version of the Canon Digital Rebel, for instance, you might need to edit the Model annotations in profiles that were created using the American version of the same camera.
The Clear button will reset all fields to undefined.
The Auto Fill button will attempt to read EXIF data from the current image and fill in corresponding values automatically. It will only change a field if it can locate corresponding data in the EXIF record. So, depending on the situation, you might want to hit the Clear button first, to erase any spurious values from an existing profile.
For descriptions of individual annotation fields, click on the "What's This" help button in the plug-in and then click on a field.
See the discussion of "How many profiles do I need?" for more information about the relative importance of different annotation fields.