Think about Canada's retirement income system as comprising three tiers: OAS and GIS are the first tier, the Canada Pension Plan is the second tier, and registered pension plans and RRSPs are the third tier. While the majority of women in the private sector do not have a registered pension plan, the extent to which they can contribute to RRSPs is there as the alternative savings vehicle, with higher contribution limits set for those who don't have the pension adjustment.
On October 20th, 2009. See this statement in context.