Article 88

A patent shall be deemed null and void if the patent holder does not fulfill his obligation to pay the annual fees within the period stipulated under this Law.

Article 89

1. The revocation of a patent by operation of law shall be notified in writing by the Directorate General to the patent holder and the licensee and shall be effective as of the date of notification
2. The revocation of a patent on the grounds as referred to in Article 88 shall be recorded and announced.

Article 90

1. A patent may be revoked in whole or in part by the Directorate General upon a written request from the patent holder to the Directorate General
2. The revocation of patent as referred to in paragraph (1) may not be carried out if the licensee has not given a written consent to be attached to the request for revocation
3. The decision to revoke a patent shall be notified in writing to the licensee by the Directorate General
4. The decision to revoke a patent on the grounds as referred to in paragraph (1) shall be recorded and announced
5. The revocation of a patent shall be effective as of the date on of the stipulation of the decision of the Directorate General.

Article 91

1. A lawsuit for revocation of a patent may be granted where:
   1. The relevant patent should not have been granted according to Article 2, Article 6, or Article 7,
   2. The relevant patent is the same as another patent that has been granted to another person based on this Law,
   3. The grant of a compulsory license cannot stop the implementation of the relevant patent in the form and manners which contravene the public interest within the period of
2. (two) years commencing from the date of granting of the relevant compulsory license or from the date of granting of the first compulsory license in case some compulsory licenses have been granted
3. A lawsuit for revocation on the grounds as referred to in paragraph (1) item a may be filed by a third party against the patent holder to the Commercial Court
4. A lawsuit for revocation on the grounds as referred to in paragraph (1) item b may be filed by the patent holder or the licensee to the Commercial Court requesting the revocation of the other patent which is the same to his
5. A lawsuit for the revocation on the grounds $S referred to in paragraph (1) item c may be filed by the public prosecutor against the patent holder or the compulsory licensee to the Commercial Court.

Article 92

If the lawsuit for revocation of a patent as referred to in Article 91 shall be confined to one or several claims or parts of claims, the revocation shall be granted only with respect to matters for which revocation is sought.

Article 93

1. The decision of the Commercial Court on the revocation of a patent shall be forwarded to the Directorate General at the latest 14 (fourteen) days as of the date of the decision
2. The Directorate General shall record and announce the decision on revocation of a patent as referred on in paragraph (1).

Article 94

The procedure of filing a lawsuit as referred to in Chapter XII of this Law shall apply mutatis mutandis to Article 91 and Article 92.