It indicates that the information is available, but due to some reasons the application decided not to supply it right now. If a module needs some extra information, it puts a request into the prompts list. The field of items in this list have the following meaning. Such an item may be present and marked as unavailable. A question is an item with data being NULL and len being 0.
Every module looks through the list of questions and tries to figure out the answers.
If the module is the first one to find the answer, it fills data and len fields of the item that contains the question. Override modules just erase answers that are incorrect from their point of view and put correct ones. 2.4 List-processing functions Both modules and applications quite often have to deal with item lists. This function takes an item and inserts it to the list. This function takes an item in the list and removes it from this list.