Variants of a mold are catalogued separately, so each one has its own sets and minifigs. Check these too if something you expect is missing here.

• 3004 Brick 1 x 2 this part is a alternate of it
• 3065 Brick 1 x 2 without Bottom Tube this part is a alternate of it
• 3065b Brick 1 x 2 without Bottom Tube, Slotted (with 1 slot) this part is a mold of it