India has strong systems in place to check the quality of patents. The validity of patents can be challenged under: Sec 25(1): Pre-grant opposition: Under this section, a patent cannot be opposed by anyone at any time after publication of the patent application but before his deliverance. Pre-grant opposition procedures are ex parte. Article 25(2): Opposition after grant: Under this article, "any interested person" may oppose the patent within one year from the publication of the date of grant of the patent. Oppositions to grant are interparteesSec 64: Revocation of Patent: Under this section, a patent may be revoked at any time during the life of a patent by an interested person. Pre- and post-grant oppositions provide pre-litigation mechanisms to challenge validity. of patents. They can be used to challenge the patent owner's unsubstantiated claims without going to court or violating the patent, both costly options. A person may also file a petition for revocation with the Intellectual Property Appeal Board (IPAB). ). The revocation proceedings can take place before the Appeal Commission while the High Court will only entertain the revocation proceedings when a counter-claim is made by the alleged infringer. 3.3 Appeal: In the event of oppositions subsequent to delivery, unlike oppositions prior to delivery, the decision of the controller may be appealed to the Appeals Commission. A request for patent invalidation is the most frequently used defense in patent infringement litigation. The existence of a valid patent is the prerequisite to any action for patent infringement. In patent infringement disputes, the court will not directly deny the validity of a patent and will only make a decision on patent infringement after...... middle of document...... specification provisional in a signatory country to the conventionj) Incorrect mention of the source/geographical origin of the biological material. If the invention uses biological material, this material must be deposited with an international depositary authority to complete the application on or before the filing/priority date. In addition, the source and geographical origin of the biological material specified in the specification must also be disclosed therein. The sequence listing is submitted electronically and may also be numbered in the specification if necessary in the case of biotechnological inventions. k) Anticipatory invention with respect to traditional knowledge of any community, anywhere in the world. The invention claimed in any claim in the full specification is not new in relation to prior knowledge, traditionally known to the local communities of India.