# Recommendation X.420 (11/1988): Message handling systems: Interpersonal messaging system

> superseded recommendation/international standard from the International Telecommunication Union

**Wikidata**: [Q26985510](https://www.wikidata.org/wiki/Q26985510)  
**Source**: https://4ort.xyz/entity/recommendation-x-420-11-1988-message-handling-systems-interpersonal-messaging-system