D.C. United released a teaser video for their new primary jersey, set to be released on January 19 (the same day as the MLS SuperDraft).
At the end of the video, they give a quick tease of a part of the 2018 primary jersey, which we have isolated:
Sneak peek from @dcunited of what looks like the neck tag of their new jersey, featuring DC diamond and the lat/long of Buzzard Point (I assume) #dcu #mls pic.twitter.com/HE4w9tFfWG
— Ben Bromley (@BRUBromley) January 10, 2018
To my eye, that looks like the neck tag of the jersey, with the latitude and longitude of Audi Field printed on it.