37 CFR §222.17

1. (a)General. A party may request to withdraw its own claim or counterclaim by filing a written request with the Board seeking withdrawal, and therefore dismissal. Such written request shall consist of a brief statement seeking dismissal and shall follow the procedures set forth in § 220.5(a)(1) of this subchapter.
2. (b)Withdrawal before a response. If the written request is received before a response to the claim or counterclaim is filed with the Board, the Board shall dismiss the claim or counterclaim without prejudice, unless all parties agree in a written stipulation filed with the Board that the claim or counterclaim shall be dismissed with prejudice.
3. (c)Withdrawal after a response. If the written request is received after a response to the claim or counterclaim is filed with the Board, the Board shall issue a final determination dismissing the claim or counterclaim with prejudice, unless the Board determines in the interests of justice that such dismissal shall be without prejudice or all parties agree in a written stipulation filed with the Board that the claim or counterclaim shall be dismissed without prejudice.
4. (d)Effect of dismissal. Dismissal of a claim or counterclaim under this section will not affect any remaining claims or counterclaims in the proceeding.