For the purposes of this document, the following abbreviated terms apply:
| ASCII | American Standard Code for Information Interchange |
| CDRS | concept dictionary resolution services |
| DTD | document type definition |
| HTML | HyperText Markup Language |
| IG | identification guide |
| IRDI | international registration data identifier |
| OTD | open technical dictionary |
| RA | registration authority |
| RAI | registration authority identifier |
| RFC | request for comments |
| SOAP | Simple Object Access Protocol |
| UML | Unified Modeling Language |
| URI | uniform resource identifier |
| URL | uniform resource locator |
| XML | Extensible Markup Language |
| WSDL | Web Services Definition Language |