This paragraph is really too specific. A notation is a name and an external identifier; the idea is that it's supposed to be helpful in figuring out how to deal with the data to which it's attached. The suggestion that the XML processor itself might do something with the notation is really bogus; that's not its job. So if anyone is interested, it would have to be the application, not the XML processor. Furthermore, the application might be able to handle the data itself without any help, once it knows the notation.
Back-link to specCopyright © 1998, Tim Bray. All rights reserved.