# Recommendation E.164 (11/1988): Numbering plan for the ISDN era

> superseded recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q26985347](https://www.wikidata.org/wiki/Q26985347)  
**Source**: https://4ort.xyz/entity/recommendation-e-164-11-1988-numbering-plan-for-the-isdn-era