This tag is replaced by a URI referencing the current page and includes a query parameter that will be automatically checked by BIS to ensure proper sequencing of requests. BIS will check any requests to the current session and will reject (displaying an error page) any request that does not contain the query parameter served by the FormActionTarget tag. By using this tag, the service program may assume that any requests that return control to the service are in the sequence expected by the program.
The FormActionTarget tag should normally only be used as the value of the action attribute of an HTML <form> element. In any case it must be used in such a way that the next expected request will be directed to the URI represented by the tag.
If a response page rendered by BIS does not contain the FormActionTarget tag, no sequence checking will be performed by BIS. The service program may, of course, perform its own checking using other means, such as hidden fields, if required.