# Recommendation I.330 (11/1988): ISDN numbering and addressing principles

> recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q27051412](https://www.wikidata.org/wiki/Q27051412)  
**Source**: https://4ort.xyz/entity/recommendation-i-330-11-1988-isdn-numbering-and-addressing-principles