As far as I am aware, within the UK DRL's were made mandatory for all new vehicles to have them. I haven't seen an option on my car for this, and I assume that all cars sold in the UK have had this option removed for legal reasons.
I guess the manual is trying to cover a multitude of countries and therefore give the option for those where the law isn't so prescriptive.
If anybody knows different, let me know, cheers.
Yorks500L