Initiates when the form filler attempts to enter more than the maximum allowed amount of content into a field. For example, if the Limit Length property for a field is set to 5, and a form filler attempts to enter the string abcdef, the full event initiates when the form filler types the letter f.
Use this event to indicate to a form filler that a field has reached its maximum capacity. For example, you can output a message to the form filler indicating that the field is full and provide any steps that should be taken to correct the issue.
See also 

full event