How to reproduce:
1. Open the attached project (SpriteBorder.zip)
2. Open the Sprite Editor Window
3. Inspect the "Map__16_Checker" asset in the Sprite Editor
4. Notice how the value of 200 is assigned to the "T" field rather than "B"

Expected result: The border with the value of 200 is labeled as "B" and not "T"
Actual result: The border with the value of 200 is labeled as "T" and not "B"

Reproducible with: 2018.2.0a4, 2018.2.11f1, 2018.3.0b4, 2019.1.0a2
Not reproducible with: 2017.4.0f1, 2017.4.12f1, 2018.1.9f2, 2018.2.0a3

Notes: It doesn't seem like the fields are simply mislabeled, as the value of 200 jumps fields between versions