According to an article published in BIMCO, from 1 March 2020, not only the use of fuel oil with a sulphur content exceeding 0.50% will be prohibited.
Ban on fuelEven carrying fuel oil intended for use onboard that ship, with a sulphur content exceeding 0.50%, will be prohibited, unless the ship is equipped with a certified equivalent such as an exhaust gas cleaning system (scrubber).
Yet, from 1 January 2020 (when the IMO 0.50% sulphur regulation takes effect), some ships may have non-compliant...
http://mfame.guru/is-blending-of-fuel-allowed-onboard-ships-after-imo-2020/