§ 1065. Incontestability of right to use mark under certain conditions

Except on a ground for which application to cancel may be filed at any time under paragraphs (3) and (5) of section 1064 of this title, and except to the extent, if any, to which the use of a mark registered on the principal register infringes a valid right acquired under the law of any State or Territory by use of a mark or trade name continuing from a date prior to the date of registration under this chapter of such registered mark, the right of the registrant to use such registered mark in commerce for the goods or services on or in connection with which such registered mark has been in continuous use for five consecutive years subsequent to the date of such registration and is still in use in commerce, shall be incontestable: Provided, That -