I’m Korean, and in Korea we don’t usually use weird patterned numbers like that under signs, so I noticed it right away
바다의 파도
I think the numbers below the sign probably mean something like this
If you compare it using the A1Z26 cipher
- 04 → D
- 13 → M
- 26 → Z
DMZ is the demilitarized zone in Korea
20 26-06-07 (xbox show day)