Section 13(1)(b) in Special Marriage (High Court) Rules, 1955
(b)Where the written statement of the respondent alleges adultery by the petitioner with a named man or woman as the case may be, a certified copy of such statement or such material portion thereof containing such allegation shall be served on such man or woman, accompanied by a notice that such person is entitled within the time therein specified to apply for leave to intervene in the cause.