Help undstanding 396xt

[FFAndy]

I could use some help understanding what do these settings do if i have them checked while programming my 396xt scanner using free scan?
Use Motorola end code
use digital motorola end code
enable analog AGC
enable Digital AGC
20dB attenuation.

Also what is P25 ERR rate on freescan that shows next to singnal strength?
And do any of these setting help making the voice not sound like a robot and more like a human? Thanks in advance for your help

 

[UPMan]

End Code: TemplateSetEndCode < UnidenMan4 < TWiki
AGC: BCD996XTSettings < UnidenMan4 < TWiki

Attenuation: TemplateSetAttenuator < UnidenMan4 < TWiki

 

[W8RMH]

Easier to Read BCD396XT Digital Scanner Manual