Title and Description are mandatory - how do I change this? Customer example: "I would like to make the title and description non mandatory on the closure window (as we have added a category field which is often sufficient to explain the closure reason).However, the "mandatory = true" setting is greyed out in window designer so I am not able to change it."
These fields are actually mandatory at the object level so cannot be added to the window as non mandatory. However depending on the business requirement you could find alternative workarounds.
With our closure window customer example, you can autopopulate these fields with some standard texxt when the closure category is selected though. Article 207 shows you the theory of how this can be done - the example is a different application but the theory of how to configure this is the same.
ITBM Window Manager and Window Designer