Unknow dat files in some 1050 maps

Can anyone explain me where the arp_*_*_*_*_f.dat files are for ?
These are in the Benelux and DE_AT_CH maps but not in the Scandinavia map
I don´t know yet if they exist in Europe maps

What is the different between the 1050-10209 truck map which is 785MB and 1050-10210 which is 4GB ?

The 1050-10209 truck map is 4.7GB and for nav3 devices with navcore 9.xxx

The arp files are for Mazda and Nav 3 devices you can delete them and also cphonmlh
You can instead use a little tool for optimize nav 3 maps for use in nav2 devices,
[Please Register or Login to download file]
Look at the chart
maps-v1xxx/tomtom-1050-maps-t21730.html

Thanks, I have a 750GO with navcore 9.702 so I can delete the arp files ?!
I can´t get 10209 complete it is just one rar file of ±800MB. I try it later again
I also download 10210 and that one is complete (4,95GB)