Range Finder Guide

Range Finder    need easier or explain the settings 

Range Finder Zeroing if Zoomed

Zeroing Range /Finder Zeroing  (Zoom)

firing mode /Zeroing /Range finder Zero 

to me they all say same thing why not make it more simple and just add

firing range finder 

where can we find more info on same  for the exact setting to make the range finder work and to use it douring firing  and zoomed