The first two categories are fairly easy to define and manage. The third category, Cash Flow Liquidity, is a little tricky. It is the volume and timing of principal payments or maturities from assets. This third component of liquidity risk is one that I believe needs more attention. As we've said, there is always a tradeoff.
Liquid assets have short maturities but are low yielding.
As regards Cash Flow Liquidity, the tradeoff has to do with the uncertainty of when precisely an asset will return its principal. If the uncertainty is high, either because of prepayment risk, or call risk, then the yield will be higher, but market value fluctuation will be greater and the bond will be less liquid. Oh, that's not to say that it can't be sold. However, management of the securities portfolio has become more complicated with the proliferation of new financial instruments and investment types. The remainder of the portfolio should be managed within limits on how much cash flow uncertainty to accept.