1. An apparatus for deferred topic data handling in a publish/subscribe apparatus comprising a publisher for publishing a first message and a subscriber for receiving the topic data in a second message, the apparatus comprising: a processor; a memory; a computer handler for handling the first message published by the publisher, the first message comprising an instruction, said instruction comprising a function with an associated parameter; a comparator for comparing said function with a first storage component in order to determine whether said function is stored in said first storage component; a generator for using said function and said parameter data to generate the deferred topic data; and an inserter for inserting the deferred topic data into the second message for distribution to the subscriber.