The principle of 'generalia specialibus non derogantits' and the rule of construction of fiscal law require that any ambiguity in the matter of construction of fiscal law should be resolved in favor of the taxpayer rather than the Revenue.

In these four writ petitions, the petitioner is one and the same. In three writ petitions, namely, W.P. 2054, 3257 and 3258 of 1983, the petitioner.

"prays for writs of mandamus directing the respondents to permit the petitioner to clear the imported items of machinery without payment of auxiliary duty under the Customs Law. In the fourth writ petition, namely, W.P. 2055 of 1983, the petitioner prays for a writ of mandamus to direct the Union of India to grant exemption to the petitioner under Section 25 of the Customs Act, 1962 with regard to payment of auxiliary duty on items of machinery imported by it. The petitioner has no grievance with regard to the payment of basic Customs duty on the items of machinery imported by it.

2.The petitioner has imported the concerned items of machinery pursuant to specific contracts registered under Heading 84.66 to the First Schedule to the. Customs Tariff Act, 51 of 1975. The petitioner has enjoyed the concessions annexed to the imports made pursuant to such contracts with regard to basic Customs duty and additional duty. The problem presented to the petitioner and equally so, to the Revenue is with reference to the auxiliary duty on the items of machinery imported by the petitioner. According to the petitioner, specific items 'paper making machinery and component parts thereof falling under Heading 84.31 imported by it have been totally exempted from auxiliary duty as per Notification 62/83-Customs, dated 1-3-1983. According to the Revenue, since the above items are also those imported pursuant to the specific contracts registered under Heading 84.66, they have to bear the auxiliary duty to the extent of 20% of the value as per the Notification 61/83-Customs, dated 1-3-1983. The body of the Notification 62/83-Customs, dated 1-3-1983 and the relevant items of the Table relatable to Heading 84.31 are extracted as follows:

In exercise of the powers conferred by sub-section (1) of Section 25 of the Customs Act, 1962 (52 of 1962), read with sub-clause (4) of Clause 45 of the Finance Bill, 1983, which clause has by virtue of the declaration made in the Bill under the provisional collection of Taxes Act, 1931 (16 of 1931), the force of law, the Central Government, being satisfied that it is necessary in the public interest so to do, hereby exempts the goods specified in Column (3) of the Table annexed hereto and falling under Heading No. or sub-heading No. of Heading No. of the First Schedule to the Customs Tariff Act, 1975 (51 of 1975), specified in the corresponding entry in the Column (2) of the said Table, when imported into India, from the whole of the auxiliary duty of Customs leviable thereon under sub-clause (1) of Clause 45 of the said Finance Bill.

The body of the Notification 61/83-Customs, dated 1-3-1983 and the relevant item of the Table relatable to Heading 84.66 read as follows :

"In exercise of the powers conferred by sub-section (1) of the Section 25 of the Customs Act, 1962 (52 of 1962) read with sub-clause (4) of Clause 45 of the Finance Bill, 1983, which clause, has, by virtue of the declaration made in the said Bill under the Provisional Collection of Taxes Act, 1931 (16 of 1931), the force of law, the Central Government, being satisfied that it is necessary in the public interest so to do, hereby exempts the goods specified in Column (3) of the Table annexed hereto and falling within the Chapter of the First Schedule to the Customs Tariff Act, 1975 (51 of 1975) specified in the corresponding entry in Column (2) of the said Table, when imported into India, from so much of the auxiliary duty of Customs leviable thereon under sub-clause (1) of Clause 45 of the said Finance Bill, as is in excess of the amount calculated at the rate of twenty percent of the value of such goods as determined in accordance with the provisions of Section 14 of the First mentioned Act.

3.Two salutary principles come to the aid of the petitioner to sustain its prayers with regard to total ex