The only criterion (apart from eligibility to vote) that applied to any register for which I submitted a form was that of age. If you were over the age limit, you did not get a "J", and if you were below it you did. Being under the age limit, I received two jury summonses while I was ineligible for professional reasons. It was up to me to return the summons saying why I was not eligible (or, as the case might be, exempt or disqualified). However, I recall that at an earlier time there was provision for identifying householders, I think by requiring their names to be placed first on the form. If I remember correctly, the first-named was taken to be the householder (and therefore liable under the law at that time) unless it was made clear that there were joint householders. Jeremy Wilkes