Confusing ya I know
In words
Unity3d Part:
Open Unity
Import Image
Rename it to decal if it’s not already
Tick sRGB Color Texture
Make Alpha Source Input Texture Alpha
Tick Alpha is Transparent
Bundle using the tool that Nelson provides
Once Bundled:
English.dat
Name Name of decal
Name.dat
Type Decal
ID # Number
Decal_X # Width
Decal_Y # Length
Decal_LOD_Bias 1
Asset_Bundle_Version 2
Final Product in the files
Final Product in-game (the blocky edges are from testing they should look like normal following the above)

This is what i mean
What yours should look like
Add me on steam if you have questions
http://steamcommunity.com/id/Vulblight/