NetSuite Forms

NetSuite uses forms to control the input of a Sales Order, Estimate or Invoice. You can specify a form by using this in the URL

Forms can be referenced either via another field (which contains NetSuite Form Id) on the originating object, or as a text field in the formula. So you may use either approach:

&custom_form=custom_form_api_field__c

&custom_form="123"

(NetSuite accepts a form ID, rather than a form name)