1. A method, comprising: receiving a triggerable declarative object (TDO) at a digital television receiver device that carries out a programmed script upon execution; the programmed script including a programmed function and a parameter discovery function that determines an existence of a particular value for an operational parameter of the television receiver device, the operation parameter of the television receiver device corresponding to capabilities of the television receiver device required by the programmed function; initiating the execution of the TDO in order to initiate execution of the script on a processor of the television receiver device; and running the programmed script on the processor of the television receiver device in order to determine the existence of the particular value for the operational parameter and in order to execute the programmed function, wherein execution of the programmed function is conditional upon the determined existence of the particular value for the operational parameter of the television receiver.