What's the difference? Half-staff and Half-mast

what's the difference between flying a flag at half staff or half masked they both mean the same thing American English makes a distinction between whether a flag is being flown on land or at sea at Sea you would use half mask where the ship has a mask and on land you would use half staff in reality people use the terms interchangeably but the US flag code presidential proclamations the AP style guide they all use half staff for flags on land in the rest of the English thinking World half masted is the only term used I sure wish we didn't need the term at all