The third of the set, for the Z velocity at +16, and never called: HOMER tests only the U and V bits of what it bumped into, and no other code or table holds this address. sna2ctl left it as data because no session ran it; its nine bytes are LD A,(IX+$16), NEG, LD (IX+$16),A and RET, the pattern of BOUNCE_U and BOUNCE_V with the next offset.