What do they mean????

[R Bischof]

Hi,
I have to admit that I have no idea what SUN means with the following sentence taken from my spec:
"Your user interface should be designed with the expectation of future functionality enhancements, and it should establish a control scheme that will support this with minimal disruption to the users when this occurs. "
How do I design a user interface in a way that it is expandable to ANY not yet defined functionality enhancements with minimal user disruption? Not from a technical point of view but only regarding GUI design and process flow?
Any ideas?
Rainer