One exception is 【that for all submissions and revisions prior to final acceptance,it is preferred {that where possible,tables and figures appear within the body of the manuscript soon following the point *where they are first discussed and not in separate files*}】
总感觉这句句子打错了点什么……
不管正常不正常,is应该是谓语.【】是is后面的表语从句,{}是preferred后面的宾语从句(这句句子里可能打错了单词吧……不太能理解,所以那个where就不能解释了……),**是修饰point的定语从句.大概就是这样了……