The likely reason why you cannot use the Record ID to be unique is that suppose you were creating a record. QuickBase first has to save the record to determine the Record ID. But then if it is supposed to enforce uniqueness then it would have to block the save because the value is not unique so at that point it's actually too late to block the save because it already created the Record ID.
Having said that, if in fact you have a concatenated field which includes the Record ID then by definition it is unique because as you said the Record ID is unique. So you have no need to mark that field as needing to be unique because it will be unique.
------------------------------
Mark Shnier (YQC)
mark.shnier@gmail.com
------------------------------
