An event trigger data string is formulated and added to digital content for distribution to an audience via broadcast, satellite, cable or any other technology. The event trigger data string includes identification of an event source, identification of an operation to be performed, and a payload. A controller reads the data string and outputs a command to an appropriate event source for alteration of a digital content stream based upon the identified operation. The payload may, for example, identify an advertisement or notice to be spliced into or out of the digital content stream. Such event trigger data strings may be added to many different digital content streams, and a router or switching component may distribute the streams to systems that disseminate them to the audience. The technique enables interaction with different event sources, and allows command of multiple different operations by these event sources.