11. How and on what grounds can I challenge a patent?

Under section 91 of the Patents Ordinance, any person may apply to the court to revoke a patent for an invention. There are a number of grounds on which the application may be brought, including the following:

that the invention was not patentable (i.e. that the invention was not new, did not involve an inventive step and was not susceptible of industrial application).
that the specification of the patent does not disclose the invention in a manner sufficiently clear and complete for it to be performed by a person skilled in the art.
that the matter disclosed in the specification of the patent extends beyond that disclosed in the application for the patent as filed.