23. For the purposes of section 56 of the Act, the member who contributes to a voluntary retirement savings plan may, at any time, set his contribution rate at 0%. However, the member who as an employee participates in a plan offered by his employer may set his contribution rate at 0% where he has contributed for at least 12 consecutive months since his registration, or before that time period where tax rules no longer allow him to contribute amounts to the plan, provided he pays into the plan an additional contribution equal to or greater than the contribution determined for that period or where his employer contributes on his behalf.