Indigo is right, it is just anti-aliasing. This is what happens when people blindly recite arbitrary rules (such is the anti-45-aa) without holistic consideration, it leads to people being confused like this. What also leads to confusion is the mixing up of definitions; so called "sub-pixelling" is antialiasing. And so is "weight due to value". They're all one and the same. If ever a special reference topic was needed, it would be one which cleared up people's misconceptions of those kind of terms.
