As a substantive law requirement considering unity of invention, reference is made to Art. 45, the Decree Law #551 and Art. 15 Reg. DL #551. It is to be noted that the lack of unity opinion by the Turkish PTO at an early formal examination stage of the examination is of a priori nature, within the meaning of the EPC (EPO Examination Guidelines F.V.7).

Therefore, when the Turkish PTO examines the application for compliance with the requirements of Art. 42 to Art. 52 DL #551, the unity of the invention is also examined though it is not a formal issue. It is worthy of note that a substantive law requirement is checked at this point under formalities examination before the Turkish PTO.

As an application can relate to one invention or a group of inventions combined to create a general single invention (Art. 45 DL #551), when the application does not comply with requirements of Art. 45 DL #551, the applicant is then notified that the application should be restricted to one invention. Accordingly, the examination procedure is suspended at this stage and the applicant is given a three-month period to overcome the unity objection of the Turkish PTO.

As is known, a posteriori examination of unity of invention may reveal that the common special technical feature in some of the claims has become part of the state of the art considering the cited prior art documents. However, although carried out under the formal examination of the Turkish PTO, a priori findings relating to lack of unity can also be communicated to the applicant as explained above.

Simultaneously, the applicant can be notified that the application should be divided within six months from such notification date provided that the parent application is still pending on the date of filing the divisional applications.