It was recently discovered that the cloak of elvenkind and Keoghtom’s ointment magic items were not in the Basic Rules. The D&D Expeditions that they were given out in said the items were in the Dungeon Master’s Guide, but since the DMG has been delayed a couple of weeks the item details were nowhere to be found.
Thankfully, Wizards of the Coast responded quickly to the discovery and made a quick update to the DM Basic Rules, adding the two items.
You can go to the Wizards’ Basic Rules page to download the new V3 DM Rules.