[Zope] <dtml-with> confusion

[Dan L. Pierson]

Chris Withers writes:
 > Can someone explain the difference between:
 > 
 > <dtml-with "PARENTS[-1]">
 >  <dtml-with squishdot>
 >  ...do stuff here...
 >  </dtml-with>
 > </dtml-with>

Push the root (PARENTS[-1]) on the namespace stack.
Push squishdot on the namespace stack.
...do stuff here...

 > <dtml-with "PARENTS[-1].squishdot">
 >  ...do stuff here...
 > </dtml-with>

Push PARENTS[-1].squishdot on the namespace stack.
...do stuff here...

Now, when would this make a difference?