Gips cash allocation

It says you need to include cash unless the manager does not have discretion over the amount of assets that is allocated to cash. Would there be a time where a manager did not have discretion over amount of assets allocated to cashand the portfolio was still a discretionary portfolio to be include in a composite? I guess there must be a situation since why else would they mention this?

If i hire an external manager and he manages $100M, I have no control over his cash position outside of setting a 5% max If I have a balanced portfolio with a FI and Equity manager and a small cash position, then I do have control b/c its outside the manager.