Thanks for your prompt reply
Your idea of a new table linked to the 'isys_cats_enclosure_list' looks like a good solution. It could be called something like 'isys_cats_enclosure_pos' and would require the following fields:
isys_cats_enclosure_pos__id
 isys_cats_enclosure_pos__isys_cats_enclosure_list__id
 isys_cats_enclosure_pos__u
 isys_cats_enclosure_pos__isys_obj__id
Btw there is 1 other table linked to 'isys_cats_enclosure_list' called 'isys_pos_gps', could you tell me what is the purpose of this table?
Regards,
Nik