I have a file for which ExifTool returns data for a tag named xmp-exif::DateCreated.
But this tag is not included in the list of tags my software imports via ...-listx.
I've made a quick check via: -list -xmp-exif:all to be sure and the tag is not listed.
This makes the tag invisible for users of IMatch. Is there anything special about this tag?
It contains a detailed timestamp with time-zone offset.
Exiftool returns that value with two colons? I'd be interested in seeing that section of the raw XMP.
Otherwise it sounds as if the source app is making up their own tag and not reading the specs. Exiftool doesn't write an XMP-exif:DateCreated tag. I looked through the EXIF for XMP specs and closest tag in name is the XMP-xmp:CreateDate. It seems more likely they're misreading the IPTC specs which use XMP-photoshop:DateCreated.
That's all conjecture on my part, of course.
ExifTool returns it as
[XMP-exif] Date Created : 2015:06:06 10:54:52-07:00