Strategy, page-21

I think you may find the $5000 f/c limit is the total f/c you receive in a year

From the ATO

You need to meet the anti-avoidance rules to qualify for a refund.

If your total franking credits entitlement is $5,000 or more, regardless of whether
your shares are a single parcel or a portfolio made up of several parcels, you must
meet the:
holding period rule
related payments rule

If your total franking credits entitlement for the income year is less than $5,000 you
only need to meet the related payments rule.

You are entitled to a franking tax offset only for those shares that satisfy the
relevant rule or rules. If you cannot claim a refund, do not include those franking
credits in your assessable income

So if you receive more that $5000 in dividends in a year you have to satisfy the holding period rule (45+2)