Generated text may come from external files/applications or be built into the FOSI itself. If from an external source there is usually some form of call through an <att><specval> combination to access the desired information.
There are also a couple of reasons why generated text may not 'automatically' appear. First the 'full' or 'partial' auto updates may not be turned on. Secondly, and I have this problem for my current document, it may be too large for 'auto updates' to occur. If the file is too large you should (and I get this with 5.4 and later) a message window stating the file is too large for auto updating.