In its bid to overturn the assailed Decision and Resolutions, OSCI foisted several procedural issues all based on the Rules of Court, the application of which it anchors on Sec. 3, Rule I of the NLRC Rules of Procedure then prevailing, which pertinently provided:   Section 3. Suppletory application of Rules of Court and jurisprudence. — In the absence of any applicable provision in these Rules, and in order to effectuate the objectives of the Labor Code, the pertinent provisions of the Revised Rules of Court of the Philippines and prevailing jurisprudence may, in the interest of expeditious dispensation of labor justice and whenever practicable and convenient, be applied by analogy or in a suppletory character and effect.44 [44]     OSCI argues that the Complaint of Bastol ought to have been dismissed at the outset, i.e., before the labor arbiter level, since it is an initiatory pleading which lacked the mandatorily required certification of non-forum shopping under Sec. 5,45 [45] Rule 7 of the Rules of Court. 44[44] The New Rules of Procedure of the National Labor Relations Commission, issued on August 31, 1990 at Cebu City by NLRC Chairman Bartolome S. Carale. 45[45] SEC. 5. Certification against forum shopping. — The plaintiff or principal party shall certify under oath in the complaint or other initiatory pleading asserting a claim for relief, or in a sworn certification annexed thereto and simultaneously filed therewith: (a) that he has not theretofore commenced any action or filed any claim involving the same issues in any court, tribunal or quasi-judicial agency and, to the best of his knowledge, no such other action or claim is pending therein; (b) if there is such other pending action or claim, a complete statement of the present status thereof; and (c) if he should thereafter learn that the same or similar action or claim has been filed or is pending, he shall report that fact within five (5) days therefrom to the court wherein his aforesaid complaint or initiatory pleading has been filed.