Absolute values changing without movement

I’m using a Fanuc 10t model f, whenever a code is produced using the conversational fapt it uses G50 x z. X and Z values are what I input as machining start position. Is there a parameter I need to change to stop it calling G50 and just use the tool off sets? Or where would I find a comprehensive list of parameters and there meanings?

That is the manual
https://www.amazon.com/Fanuc-Operato.../dp/B004THDH96

Early I found it on cncmanual.com for free