The IPVN shall be responsible for settling the third-party opposition and sending its settlement result to the opposers. For the international trademark application designating Vietnam under the Madrid Agreement and Protocol, the time limit for submitting a third-party opinion is regulated differently. Procedure for settlement of third-party oppositionApplications for third-party opposition must be made in Vietnamese. Choice of opinion or oppositionWhile both mechanisms allow third parties to challenge a trademark application, they differ significantly in their legal nature. A trademark opposition is a formal, rigorous and highly adversarial proceeding between the parties.