Nose weight

It will be written down in your car's manual somewhere. I think (maybe wrongly) that the towbar will take whatever your car can. One car I had was 75Kg and now it is 100Kg

Also check your caravan's documentation too.

The weights you require will be on labels on the caravan coupling and the vehicle tow bar.

Rigs1946, not quite sure what you are referring to when you say "maximum nose weight for your van". if you are referring to the max downward load on the tow ball then as cornersteady said it will be in your vehicle manual however there is also a maximum weight limit for the actual caravan coupling head as I referred to in my previous post.