I don't see cardinality being called out in the namespace field reference pages. Am I missing it somehow? I have to identify cardinality with a ton of fields and can share my data if desired.
From the IPTC:
"Cardinality: how often this property must or may occur in a set of Photo Metadata about an image or in a structure of a metadata property:
1 = one and only one occurrence is mandatory,
0..1 = one occurrence is optional,
0..unbounded = one and multiple occurrences are optional,
1..unbounded = one occurrence is mandatory, multiple occurrences are optional"
-J
ExifTool currently doesn't enforce strict cardinality in IPTC Photo Metadata, or XMP in general. That would be a new feature if someone was interested, but enforcing mandatory properties can be problematic.
- Phil
I'm ok enforcing it outside of Exiftool, but I'm sure it would be very useful to some. Presumably everyone deploying ET in a serious metadata environment has to enforce cardinality? I can share the data if you'd like.
- J