The Modify Family Settings page of the BIMpak Settings is used to create Modify Family map files for the Modify Family tool. The Modify Family tool is used to add parameters to a selected family.
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Note that the parameters will be written to the family in the order they are in on the Modify Family Settings window. So be sure to put the parameters in order such that if a defined parameter is used in the formula for another, then the parameter needed in the formula must be before the parameter that uses it in the formula.