My ruling is actually addressing the parent act rule. I believe it's called the parent act rule. The amendment seeks to amend section 125 of the Corrections and Conditional Release Act.
House of Commons Procedure and Practice, second edition, states at pages 766 to 767 that “an amendment is inadmissible if it proposes to amend a statute that is not before the committee or a section of the parent Act, unless the latter is specifically amended by a clause of the bill”.
Since section 125 of the Corrections and Conditional Release Act is not being amended by Bill C-21, it is inadmissible to propose such an amendment, and therefore the amendment is inadmissible.