Defines structures in STIL: 1. For the specification of resource mapping of ATE hardware architecture. An example of resource mapping is the assignment of tester resources to waveform characters that are used in STIL-vectors. 2. For including ATE specific instructions in-line with the STIL data. 3. That allow for 'incremental processing' whereby a set of STIL files may be targeted to multiple ATE systems by allowing separately identified ATE data to co-exist. 4. For defining tester rules checks to ensure that the set of generated STIL files conform to the selected resources on one or more ATE systems. 5. For the specification of the resources required for the execution of a set of STIL files on a given ATE system.