"The Perpetual Preference Shares have no fixed term and are not redeemable. Holders of Perpetual Preference Shares are entitled to receive Dividends which are fully imputed (or “grossed up” to the extent they are not fully imputed), quarterly in arrears. These dividends are at the discretion of the board of directors."

That is pretty much the definition of any PPS. Same as the banks PPS issues.
From memory the interest rate is reset every three years (I haven't checked-just saw this thread), in the recent past it has been quite low.
I have owned some of these since inception and topped up 2 or 3 weeks back.
The redemption at par is a possibility, but not something I would base an investment on.