Looking at a property defined as follows:
Property SystemTime As %Library.TimeStamp [ SqlComputeCode = {Set {*}=$ZDATETIME($NOW(),3,1,0)}, SqlComputed ];
The documentation talks about using SqlComputed and SqlComputeCode with SqlComputeOnChange (specifying which events will trigger computation), and about using them with the Calculated keyword (so it's always computed). I don't see any specific explanation of the case above, though, when neither SqlComputeOnChange nor Calculated is specified.

