A compound rule expression is created by combining two or more rule expressions. These expressions can be simple expressions, Date-Time expressions or another compound expression. The two rule expressions are joined by a Boolean operator (AND, OR, or XOR). There are a number of important considerations to be aware of when creating compound rule expressions to ensure that they return relevant and coherent results. In addition, it is important for users to understand how compound rules are evaluated so that they can be constructed in a manner to avoid unexpected or irrational results.