For a patent to be valid in Canada, the invention claimed therein needs to be new and inventive. In patent law, these requirements are known as novelty and non-obviousness. A patent cannot in theory be granted for an invention without meeting these basic requirements or at least, if a patent which does not meet these requirements is granted, it cannot later be maintained. These requirements are borne out of a combination of statute and case law. Novelty The definition of “invention” in section 2 of the Patent Act (R.S.C., 1985, c. P-4) uses the word “new”. This means the invention must not already be known. Section 28.2(1) of the Patent Act explicitly codifies the novelty requirement. Section 28.2 thus blocks patent applications if the applicant, or someone who obtained their knowledge from the applicant, made the invention public more than a year before applying; if anyone else made the invention public before the application; or if the invention is already subject to an earlier patent application. Disclosure by the applicant Paragraph 28.2(1)(a) provides a grace period that allows claims to "subject matter" in a patent (application) in Canada up until twelve months after its public disclosure by the applicant or somebody who obtained knowledge about it from the applicant. It can also allow inventors to discuss their invention with potential investors, for instance, without requiring non-disclosure agreements. However, since such a grace period is non-universal, it remains limited in its helpfulness to inventors. Disclosure by another party The section also provides that the subject-matter defined in the claim cannot have been previously disclosed in Canada or elsewhere. If the subject-matter has been disclosed in Canada or in a foreign jurisdiction, a patent cannot be granted on the same subject-matter in Canada. The section does not restrict disclosure to prior patents. As long as the subject-matter was disclosed “in such manner that the subject-matter became available to the public”, the subject-matter is barred from being patented. This includes prior patents, publications, or the invention itself being put on display. Disclosures in a private document, such as an internal memo that is not available to the public, do not count. Ignorance regarding prior disclosure is not an excuse. Where there has been prior disclosure of the same subject-matter, the invention will be deemed to be not novel, the prior disclosure being anticipatory of the invention. However, the prior disclosure must be sufficiently