*digging up that old one since it's time for an update*
Since invention of the markers, just place a new flag
, save it & click on export - then you get a neat little coordinate description:
[marker 8567 14976 Farm]
By pasting this ingame in the chat, your profile, the (ingame) forum or a telegram, you get a clickable reference to the coordinates; by changing the number (and optinally description) values, you can jump to any valid spot on the map.
The even more comfortable method is using
TW-DB's Cloth Calc Userscript - it has a neat little coordinate input field integrated in the minimap, along with a dozen of other even more useful features.
Just in case someone hasn't heard about it yet