This option in the dialog allows identification of images scanned upside-down— that is, forms fed into the scanner with the wrong side down.
Identify upside-down forms can only be selected when the job description contains at least one two-sided form definition. (To get around this, you can create a dummy two-sided form definition and include it in your job description.)
Identify upside-down forms can also be used in rare instances when a two-sided form has a front page that cannot or must not be identified or that is blank. How?
If you want to know when FORMS has used Identify upside-down forms to successfully identify a form, insert #AutoFlip into the transaction description.
If both Identify upside-down forms and Identify rotated forms are selected, FORMS first checks to see whether the form can be identified when it is rotated 180 degrees, then tries checking the other side (the back of the form), then tries rotating the other side 180 degrees. Not until all these maneuvers have been performed is the form finally given Unidentified status.
These two options can slow the identification process considerably, especially if many forms are scanned sideways or upside-down.