If CABLE is coded as XZYOV, then YZXP is code of

The coding schema pairs each alphabet with its corresponding letter from the opposite end of the alphabet series ($A\leftrightarrow Z$, $B\leftrightarrow Y$, $C\leftrightarrow X$, etc.):
* $\text{C}\to \text{X}$
* $\text{A}\to \text{Z}$
* $\text{B}\to \text{Y}$
* $\text{L}\to \text{O}$
* $\text{E}\to \text{V}$

Applying this same opposite-pair system to decode $\text{YZXP}$:

* $\text{Y}\to \text{B}$
* $\text{Z}\to \text{A}$
* $\text{X}\to \text{C}$
* $\text{P}\to \text{K}$

Thus, $\text{YZXP}$ is the code for $\text{BACK}$.