I think it refers to this situation, this is from the trust deed...

I think it refers to this situation, this is from the trust deed referring to the last CN issue

6.1 Rights Issues and Bonus Issues
(a) Subject to paragraph (b), if the Company makes a Bonus Issue or Rights Issue,
the Conversion Ratio will be adjusted immediately in accordance with the
following formula:

link ~ http://www.cbhresources.com.au/company-profile/0205_trustdeed.pdf


where:
CN means the Conversion Ratio applying immediately after the
application of this formula;
CN0 means the Conversion Ratio applying immediately before the
application of this formula;
P means the VWAP calculated in respect of the period from (and
including) the first Business Day after the announcement of the Bonus
Issue or Rights Issue to ASX to (and including) the last Business Day of
trading cum Bonus Issue or Rights Issue;
A means, in the case of a Rights Issue, the subscription price per new
Ordinary Share and, in the case of a Bonus Issue, 0;
RN means the number of Ordinary Shares issued pursuant to the Bonus
Issue or Rights Issue; and
RD means the number of Ordinary Shares on issue immediately before the
allotment of new Ordinary Shares pursuant to the Bonus Issue or
Rights Issue.