The tax was either a fixed amount per document or ad valorem where the tax varied according to the value of the transaction being taxed .
The tax was enforced by making the documents unenforceable in court if they had not been properly stamped .
The tax was either a fixed tax per document or ad valorem where the tax varied according to the value of the transaction being taxed .
The tax was enforced by making the documents unenforceable in court if they had not been properly stamped .