| SSWAP Protocol classes and properties. |
| http://sswapmeet.sswap.info/sswap/ |
| sswap | http://sswapmeet.sswap.info/sswap/ |
| rdfs | http://www.w3.org/2000/01/rdf-schema# |
| owl | http://www.w3.org/2002/07/owl# |
| xsd | http://www.w3.org/2001/XMLSchema# |
| rdf | http://www.w3.org/1999/02/22-rdf-syntax-ns# |