|| This article or section documents something not included in the current version of Scratch (3.0). It is only useful from a historical perspective.
The Set Stretch to () block was a Looks block and a Stack block. it makes the sprite set the stretch horizontally, but clears out when setting or changing size. It was removed in an early version of Scratch for unknown reasons, and it was made an obsolete block. This block is not in Scratch 2.0 anymore, but still usable in Scratch 1.4.