Specifies transparency level for the foreground (stroke) of the shape's drop shadow fill pattern, from 0.0 (completely opaque) to 1.0 (completely transparent).
Optional string. Represents a unit of measure. The default is PER. For details about PER, see Units of measure.
Optional string. Represents the element's formula. This attribute can contain one of the following strings: "someFormula" if the formula exists locally, "No Formula" if the formula is locally deleted or blocked, or "Inh" if the formula is inherited.
If the attribute is not present, the element's formula is a simple constant, for example, <element>5</element>.
Optional string. Indicates that the formula evaluates to an error. The value of Err is the current value (an error message string); the value of the element is the last valid value.