From the BD Rule Book
Training Classes/sections are open to members and non-members with
class tickets, but horses do not need to be registered. They are not qualifiersfor
Summer or Winter Regionals, but the score sheets gained in them can be
used for Area Festival qualification. No grading points will be given and results
will not affect rider status. British Dressage Rules will apply to the Training
classes. Rosettes will be given but prize money will not. Both horse and Rider
must be eligible under BD Rules for levels entered
Rosettes are given at the discretion of the organiser (especially if you're the only one in the Training Section
Your scores will be put up on the score board but won't appear on the BD web site (if you don't want your score appearing at all then enter HC).
It's a useful class if you want to try the next level up without compromising your eligibility to enter a restricted section in the current level.