Speculation about the Depths and the shelter codes
So, I've had this idea since like a week after chapter 5's release. What if the shelter code symbols also mean the places where you can enter the Depths? One of the codes has the Delta rune which could mean the main route's final location, the shelter. Another code has a Pine tree, which symbolizes the Holidays, so it could symbolize the lake that we crossed with Noelle's (Who is what the pine tree symbolizes) help. And the third code has a Police badge, which is the most obvious connection to a location. The police badge can mean the police tape which is likely to be an important location in the future since Asriel, Dess, young Noelle and young Kris explored the forest behind the graveyard that also leads to the police tape location.
So my theory is, how we'll enter the Depths, the game's final location is gonna depend on the route. You'll enter it through the shelter in the normal route, through the lake in the weird route, and behind the police tape in the aborted route.
Note: sorry if there's already a theory like this, i am not that familiar with deltarune theories. Also I acknowledge that that this is purely speculation with little to no evidence, so dont harass me if the theory is ass