Originally Posted by LindblomRJ
I believe they call it a "lug". This is what gives each course of block a 1/2" batter. This accomplishes what pins and lips on other block accomplishes. But see, lips on other block can make radiuses a pain in the hiney because you have to wack some of the lip off to make the curve.
(and in my opinion, helps keep the block from sliding forward...)
And if the lugs come out of the mold wrong (mis-shaped, defective, etc) - the block gets sold as "seconds" and we use seconds for the base course.