Gujarat Land Revenue Code, 1879
When it has been customary to levy any special or extra cess, fine, or tax, however designated, from any holder of land, which, though nominally, wholly or partially exempt from the payment of land revenue, has by the exaction of such cess, fine or tax been indirectly taxed to the State, or when any land ordinarily, or under certain circumstances, wholly or partially exempt from assessment, is subject occasionally, or under particular circumstances, to the payment of assessment, or of any cess or tax, however designated, the said assessment, cess, fine or tax may be commuted into an annual assessment on the land to be paid under all circumstances, but such commuted assessment shall not exceed such amount as the '[Collector] shall deem to be a fair equivalent of the assessment, cess, fine or tax for which it is substituted and shall not be in excess of the assessment to which the land would be ordinarily subject, if no right to exemption existed in respect thereof.