Z

zero-length string
A character string without characters, indicated by two double-quotes with nothing between them, "". A field would have such a value when you KNOW that the record has no value for this field. This is different from a NULL value, which has never been set and means more like "I don't know whether or not this field should have a value."
zoom
Print Preview: Control: ZoomTo enlarge or reduce the size of the print preview of a report. The Zoom button Button: Zoom toggles between enlarging and reducing. On the toolbar, the Zoom control has a drop list of percentages and the choice Fit, which makes the report fit into the window as a whole page.
Properties dialog: A choice for Size Mode for an image which sizes the image to fit the control but keeps the original proportions of the image.
 
Zoom window
Zoom windowA handy popup window with blank space where you can compose an expression for a calculated field in a query. It has much more visible space that the Query Design grid.