# ISO Guide 31:1981 — Withdrawn and superseded ISO standards

For ISO Guide 31:1981, item title is Contents of certificates of reference materials; status code is 9599; successor is ISO Guide 31:2000; withdrawn / published date is 1981-09-01, recorded from its source on 2026-08-05.

- **Identifier:** ISO Guide 31:1981 _(verified: appears in the quote below)_
- **Item title:** Contents of certificates of reference materials _(verified: appears in the quote below)_
- **Status code:** 9599 _(verified: appears in the quote below)_
- **Successor:** ISO Guide 31:2000
- **Withdrawn / published date:** 1981-09-01 _(verified: appears in the quote below)_

## What the source says

> 19739,GUIDE,,ISO Guide 31:1981,Contents of certificates of reference materials,Contenu des certificats des matériaux de référence,1981-09-01,1,['71.040.30'],ISO/TMBG,9599,,[33188],"['en','fr']",8,

## Source

- https://isopublicstorageprod.blob.core.windows.net/opendata/_latest/iso_deliverables_metadata/csv/iso_deliverables_metadata.csv

Last verified: 2026-08-05. Review by: 2027-02-01.
Part of [Withdrawn and superseded ISO standards](https://referencesource.org/iso-standard-supersessions/).