Registration for this year's Joint Session will be open in the next few days, and the link will be here. (Apologies if you were caught out by the earlier premature version of this wording!)
Attendees (including those presenting papers) must be members of either the Mind Association or the Aristotelian Society. You can join the Aristotelian Society from as little as £5 or the Mind Association (which includes a subscription to the Mind journal).
If you have been accepted to and intend to present at the Postgraduate or SWIP sessions, please do not select the "I'd like to present at the Open Session" option, because nobody can present more than one paper.
If you have had an abstract accepted for the Open Sessions, there is an option to tick a box saying so, and to enter the title of your abstract.
Nobody can present more than once -- so if, for example, you've had an abstract accepted for the Open Sessions, and had a different paper sent to the Open Sessions from the Postgraduate Session, you must take your pick!
The policy is to allow all Open Sessions abstracts of an appropriate standard, subject to space. In practice this could mean more accepted abstracts than rooms available, so do make sure to register early (and benefit from the lower prices).