Validates against a comma separated list of characters or words. If found in the element's data these words can be optionally replaced with another string.
Error message - The message to display next to the element if the Validation fails. This text should explain why the Validation failed and what steps the user should take to remedy the error.
Forbidden characters - A comma separated list of characters or words that must not appear in the element's data.
Match or replace
Match - if forbidden characters are found then the Validation fails
Replace - if forbidden characters are found then they are replaced with the "replace string"
Replace string - If "Replace" is selected for "Match or replace" then the matched data will be replaced with this fields text, and the form submitted (unless of course another Validation fails in the form)