XML Linking - slide "XPointer: some details"

The expression in xpointer() is, essentially, XPath, with a few extensions.
The mechanism is very robust against change
If only an element with an id should be identified, the abbreviation:
```
  href="http://abc.com/ba.xml#bradford" 
```
is also acceptable (this is equivalent to HTML!)

Applications may define and use their own scheme:

  href="http://abc.com/ba.xml#appl_scheme(something)"