The Octopre (and other Platinum units) do not come with digital outputs as standard. You can purchase a digital output card that can be easily fitted into the unit to give you a digital output. The reason for marketing the products in this way is so that people who do not require a digital output do not end up paying for one.
There are two different ADC cards available for the Octopre - one has ADAT Lightpipe out only and the 'full spec' card features ADAT Lightpipe out and a 9-pin D-sub connector which can be switched between AES and S/PDIF. Focusrite makes breakout cables for the 9-pin connector with either XLRs for AES or RCA phono connectors for S/PDIF.