I'm not saying I can't imagine how to work around it, I'm saying that we're forced to, and likely will do so in a variety of competing ways, which degrades its

I'm not saying I can't imagine how to work around it, I'm saying that we're forced to, and likely will do so in a variety of competing ways, which degrades its usefulness as an interchange format. It means your tools, at the end points or in the middle, don't know what the data in that field is and so can't do anything useful for you that you haven't explicitly taught it to do.