Some drivers are getting a little confused after the changes on 19/01/2013 so perhaps this might help to clarify a couple of things ....
For ALL those towing with a B licence no matter when they got it ....
The EXTRA rule for B licence towing is ...
The vehicle GVW added to the trailer MAM (or MTPLM) must not toal more than 3500 kgs
The rule where the trailer MAM must not exceed vehicle kerbweight is revoked for all B licence holders but the way in which the DVLA has written that is not made clear
Those that pass BOTH B and B+E after 19/01/2013 are restricted to a trailer MAM or caravan MTPLM of 3500 kgs so that is likely to affect virtually nobody unless they are towing a trailer needing more than over-run brakes
I hope that dispels a few of the confused DVLA writings on these matters
Advanced driving observer (IAM)
LGV instructor 2005 to 2008