This acronym stands for “Full Overlap,” which is what the flaps in this case do. In some cases, two panels are cut so they extend all the way to the opposite side, but in many cases all four panels are cut and designed to completely overlap. The photo above clearly shows the difference in the flap lengths on a similar size carton.

RSC stands for “regular slotted carton” and is the typical box construction that results in four flaps on the bottom box opening and four flaps at the top opening. On a rectangular box, the smaller side panel flaps are the minor flaps, and the larger, longer ones creating the box length are called the major panels. The key point distinguishing an RSC box is that the major panels meet in the middle where they are typically taped together using plastic or water-activated tape.

Half-Slotted Containers (HSC) are similar to an RSC, but with only one set of flaps. They are useful when an open-top container is desired. The top of the box is completely open. HSCs can be used to create a telescope box.