# Recommendation X.121 (11/1988): International numbering plan for public data networks

> superseded recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q26985476](https://www.wikidata.org/wiki/Q26985476)  
**Source**: https://4ort.xyz/entity/recommendation-x-121-11-1988-international-numbering-plan-for-public-data-networks