Why would you use a CodeCondition or a RuleConditionReference.

Advantages of a RuleConditionReference is that the actual rule is stored in a separate XML file with the extension .rules. This means that rules can be manipulated by other tools, for example made visible to business analysts, and even be changed at runtime.

The main advantage of a CodeCondition is that developers are more familiar with code so it may feel more natural for them. Another advantage is that complex logic may be harder to build using the rule editor than using the code editor. One confusing thing of the CodeCondition is that the result is not returned from the function but is set as the Result property on the ConditionalEventArgs property.