How do I become eligible for Diamond membership reserve?

Members who have maintained any Diamond status for at least five years during their membership lifetime (it does not need to be consecutive) are eligible to receive one complimentary Diamond membership for every 6,000 Status Points earned. 

For example, if you have held Diamond status for a cumulative total of five years and earned a total of 14,000 Status Points, you would be entitled to two complimentary Diamond memberships.

Please see Will you consider my historical Status Points and years spent as a Diamond member? for more details on how your historical Status Points and time spend as a Diamond member will be applied.