A practical use case for a fixed ID attribute?

"Costello, Roger L." <[email protected]> Sat, 8 Dec 2012 12:56:09 +0000

Newsgroups	gmane.text.xml.schema.devel
Message-ID	<[email protected]>

Hi Folks,

In XML Schema 1.1 it is possible to declare an attribute of type ID and fix its value. For example:

<attribute name="instructor" type="ID" fixed="Professor-Johnson" />

Yesterday I showed that example to my class and they challenged me on the usefulness of this. 

I could not think of a single practical use case for a fixed ID attribute.

Do you have a practical use case for a fixed ID attribute?

/Roger