[syslinux] special meaning of '--' in pxelinux.cfg

[Jodok Ole Muellers]

Hello,

I often see the double dash -- in the append line in isolinux/syslinux configurations
I only know this as "disable further option processing" e.g. in bash.

What is the function of the -- ? 
I don't see any difference if I use it don't use it.

E.g here :

append  vga=normal initrd=/install.amd/initrd.gz -- quiet 
append vga=normal initrd=debian-installer/amd64/initrd.gz -- console=ttyS0,9600n8 quiet

Thanks in advance
Jodok