The "Z" button will "zap" (erase) all previously saved games.
This button will return you to the "home" stack.
MANIPULATING INVENTORY ITEMS
To manipulate an item in the inventory, that is, an item which you have picked up at some point in the game and is displayed in the scrolling text field labeled "inventory" at the bottom left corner of the screen, click on the button labelled "examine item". You will be asked which item to examine. Make sure you enter the name exactly as it appears in the "inventory" field.
You will then be sent to the card describing that item, and you can manipulate it from there.