Signs Have Added Symbols When Reentering World

I had written on a couple of signs for a Snapshot Overview. I had exited the world, and when I returned all the signs had slashes and quotations around my text (I had only exited the world, not the game). Each time I reentered the world, more symbols appeared.

What I expected to happen was...:
The signs to remain how they were when I exited the game

What actually happened was...:
Every time I reentered the world, slashes and quotations had been added around the text, more of them each time I reentered.

Steps to Reproduce:
1. Place a sign on it
2. Leave the world, then reenter directly after
3. Observe the changed text on the sign