You really shouldn't be using XMP-PDF:keyords because this tag stores a single string and not a list of items. Also, the pipe symbol doesn't make sense as a keyword entry. If xmp:subject was a lang-alt list then you would be all set, but unfortunately with the current xmp spec you need to put all keywords in one list. But you should be able to do this using a single exiftool command with multiple tagsfromfile options. - Phil