SetShowQuestItems
Syntax:
SetShowQuestItems flag
This is used to show or hide quest items in the player's inventory (normally the player cannot drop or sell quest items). When flag = 1, quest items will be displayed in the player's inventory (default functionality). When flag = 0, quest items will be hidden.
Obviously this function has to be used in very controlled circumstances to prevent the player from permanently "losing" all his quest items.