Triggering event – Abstract
This triggering event is only available at the form level and is triggered before the entire form is validated for further processing (usually from outside, e.g. when saving via the ribbon button).
"Before validation" is not triggered when the "Validate element" behavior is executed on the form.
The actual validation round trip does NOT wait until all behaviors and actions are processed. In other words: If the form data is read and validated for further processing (e.g. to save, custom action event ribbon command, etc.), this is done regardless of what happens in the configured behavior (this means that the system does not wait for asynchronous processes).