Use of custom XMP categories

[msandersen]

A general question about creating xmp tags:
I finally managed to make a custom xmp tag, but while the default in the example config file works just fine, I am wondering what the different Categories are, and if it matters.

Code Select Expand

AngleOfView => { Groups => { 2 => 'Author' } },

The default in the example file is Category 2 => Author, but the complete list is

Category 2: Audio, Author, Camera, Device, Document, ExifTool, Image, Location, Other, Preview, Printing, Time, Unknown, Video

Are these just convenience groupings, or do they have an effect? Eg, with my AngleOfView example, could I set it to Camera? I haven't found any guidance on the proper use of these.
Thanks

[Phil Harvey]

These family 2 categories are only used to organize information when extracting with ExifTool.  They don't affect writing at all unless you do something like this:

exiftool -author:all= FILE

- Phil