Operating cash vs Free operating cash flow

So confused about the Term " Operating cash flow" and Free Operating Cash flow".

Discretionary Cash flow = Operating cash flow - Capex = Free operating cash flow - Divident

So any idea of what is the difference between Operating cash flow and Free operating cash flow.?

Please add some comments.

Thanks

These terms are specific to the S&P Framework for Credit Analysis only.

Operating Cash Flow = NI + NCC - WCInv

Free Operating Cash Flow = Operating Cash Flow - Capex

Discretionary Cash Flow = Free Operating Cash Flow - Dividends.

The full formula is provided on page 131 of Secret Sauce.