Font is rendered from a 13x13 pixel image to a 16x16 one on screen with a 3px right padding added to it.
The way BL tag works is it sets the offset xx pixels wide + 3 pixels. BL1316 strips the 3 pixel padding and makes it align perfect next to eachother.
BL1016 sets the offset within the displayed character and overwrites the displayed character by 3 pixels from the right.