]> Subject A sswap:Subject is the subject of a mapping; it is the data consumed by (input to) the service. In the concept of a service mapping an input to an output, the sswap:Subject corresponds to the input. The property sswap:mapsTo explicitly demarcates the mapping (or transformation) from this input to its output. One can also use sswap:mapsTo to describe inverse mappings where the stated relationship is from a sswap:Object to a sswap:Subject. Required predicates: sswap:mapsTo; Optional predicates: (none).