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One place this is very useful is in business rules. See the section on templatized URls in business rules for more details. However anywhere that you can use templates in your form: labels, help, hint; display message, etc... the value can either come from the value in an actual form field or from _data values that are not in any way bound to the name of a control.

_formActionUrl, _formActionMethod, _formActionTarget

The Form Action can be overridden by using these special (reserverd) URL parameter. The presence of _formActionUrl overrides any Form Action in the Form Designer by specifying which Url to go to when the form gets submitted.

_formActionMethod is optional and can be set to either "get" or "post". If unspecified it defaults to "get" causing the user to get forwarded to this web page when the form is submitted. If set to "post" it will also post the data to this Url.

_formActionTarget is optional and only taken into account when _formActionUrl is specified. It can be set to one of the values: frame, parent, top. It defaults to Frame if not specified.

When the _formActionUrl parameter is set but no Url is given (i.e. ...&_formActionUrl =&embed=...) the top frame will be closed. It is as if you set Form Action to Close" in the Form Designer.

For example... the Url http://www.frevvo.com/....&_formActionUrl=http://www.google.com, will cause the form to display google.com when it's submitted, even if in the Form Designer you had set the Form Action to be "Display Message" or one of the other options.

onInit/onSubmit

onInit and onSubmit are useful when you need to embed a  form in your own form and you want to programmatically submit the  form and initialize the form with your own document.

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