The first category of UI Validation is referred to as Pre-Validation. This is the category of validation that most people will first associate with UI Validation. Pre-Validation is a term that describes the process of determining whether or not a UI Component should be available in the UI. An example of Pre-Validation would be disabling the “check-in” action for an object that is not checked-out. Pre-Validation can be applied to both actions and attributes in the UI. Of the three types of UI Validation, this type is the most often-used.