Reduction

Reduction is Nintendo's (arguably poor) terminology for "shrink" (referring to shrinking things on the screen, i.e. modes 5, 6 and 7) and appears in the official Super Nintendo development manual.^[1]

This note also appears in fullsnes:

REPEATED EVERY 2-LINES. IF "1" IS WRITTEN, THE OBJ SEEMS REDUCED
          HALF VERTICALLY IN APPEARANCE.

See Also

• Bit Rate Reduction

Reference

1. Chapter 5. page 2-5-1 of Book I