I am not sure how it is worded in NSW but in the ACT the interpretation of abstentions is the opposite of what Jimmy T just said:
“1. the number of votes cast in favour of the resolution is greater than the number of votes cast against it; and
2. the votes cast against the resolution number less than 1/3 of the total number of votes that can be cast on the resolution by people present at the meeting (including proxy votes)…” sch.3.16(1)(a)
Ignore that the crucial number is ⅓ rather than ¼ for the ACT.
Here it is ‘votes that CAN BE cast’. So, if 100 show up for the meeting (IE they don’t stay home and ignore the meeting entirely), then the vote goes: yes-50, no-25, and 25 abstain, then the motion would pass. 50:25 passes the first hurdle of more yes than no. 25 is fewer than ⅓ of the 100 who CAN vote because they have shown up to the meeting and heard the arguments (or appointed a proxy).
It would be presumed then that 50 supported the proposal, 25 opposed and a further 25 were indifferent to which way it went, or at least were insufficiently concerned that they wanted their vote to push it one way or the other. The purpose (as I read it) of the special resolution < ⅓ opposed test is to avoid passing resolutions that have substantial opposition, albeit less than would defeat it outright by simple majority vote. People who abstain are not a substantial opposition. If you want to oppose you vote no. So, in NSW, you might perhaps have ¼ of “votes cast”, in which case I would agree with Jimmy, but it you have something like the ACT’s “votes that CAN BE cast…at the meeting”, I would disagree.