In a certain coding language, if the word 'FLOUT' is coded as 'IIRRW', then…

Concept

In an alternating letter-shift code, one fixed alphabetic shift is applied to the odd positions and another fixed shift is applied to the even positions. The position of each letter is preserved, and alphabetic movement wraps around when necessary.

Application

1. Compare each letter of FLOUT with IIRRW: F→I is +3, L→I is −3, O→R is +3, U→R is −3, and T→W is +3. Thus the shifts alternate +3, −3, +3, −3, +3.

2. Apply the same shifts to CLING: C→F (+3), L→I (−3), I→L (+3), N→K (−3), and G→J (+3).

3. Joining the transformed letters gives FILKJ.

Cross-check

Reverse the alternating shifts on FILKJ: F→C, I→L, L→I, K→N, and J→G. This reconstructs CLING, so the resulting code is FILKJ.