1. refers to newer software or hardware features that can easily be added later
2. refers to newer versions of software or hardware that the salesperson claims can easily be added later.
3. refers to capacity (such as throughput or number of ports) that you think you need, but you would be better off buying later because by the time you need that capacity the equipment is discontinued.
Note: I have a vague idea that I copied this from somewhere else, however I didn’t note down where or who. If it is yours, please let em know.