• Paris Convention for the Protection of Industrial Property; 
• Convention Establishing the World Intellectual Property Organization (WIPO);
• Agreement concerning the Trade-Related Aspects of Intellectual Property (TRIPS); and
• Patent Cooperation Treaty (PCT).

Patents of invention.

No grace period is provided for.

Patent applications are examined as to compliance with formal requirements and its novel and inventive merit.  Substantive examination has to be requested within six months of the date of filing.

Patents are valid for twenty years from the date of filing the patent application.  

Annual renewal fees are payable, from the second anniversary of the filing date, for both pending and granted patents.  There is provided for a one-year grace period within which a late annual renewal fee may be paid.

A patent must be worked within three years for the date of grant or four years from the date of filing, whichever is the later.