Evaluate a condition and perform one action if true, another if false.
The <if> element evaluates an expression and, depending on its value, executes one of two sets of activities (one if the expression evaluates to a true value, the other if it evaluates to a false value).
The <if> element may contain a <true> element and a <false> element which define the actions to execute if the expression evaluates to true or false, respectively.
If both <true> and <false> elements are provided, they may appear within the <if> element in any order.
If the condition is true and there is no <true> element, or if the condition is false and there is no <false> element, no activity results from the <if> element.