WHAT IS DISCRETIONARY SPENDING ANYWAY???

A Wall Street Journal article, a few weeks back, described how "CEOs Fight To Prevent Discretionary Spending From Creeping Back Up." I have absolutely no idea what that means....When operating in a LEAN environment, there are only two kinds of spending: Spending for activities that add value for customers, and spending for activities that do not. I don't know how either of them can be 'discretionary', or why they would 'creep back up' or why it takes special focus from a CEO to control them. Glad I run a small business and don't have to deal with "making things up" to justify my position!