---
oid: "1"
description: "International Organization for Standardization (ISO)"
last-modified: "2026-07-16"
parent-oid: ""
---

## OID: `1`

```asn1
{iso(1)}
```

"iso" is a standardized identifier, i.e. it may be used without its associated number in the ASN.1 notation.

### Description

International Organization for Standardization (ISO)

**Classification:** Standards development organization (SDO)

### Supplementary information

This OID is for ISO or IEC International Standards, and ISO Member Bodies. 
 
Operation of this OID is in accordance with [Rec. ITU-T X.660 | ISO/IEC 9834-1](https://itu.int/ITU-T/X.660) "Procedures for the operation of object identifier registration authorities: General procedures and top arcs of the international object identifier tree". 
 
All decisions related to child OIDs will be recorded as amendments to Rec. ITU-T X.660 \| ISO/IEC 9834-1 (such changes to the common text will be regarded as editorial by ITU-T). 
 
From Rec. ITU-T X.660 (2004) \| ISO/IEC 9834-1:2004, "the top-level arcs are restricted to three arcs numbered `0` to `2`; and the arcs beneath root arcs `0` and `1` are restricted to forty arcs numbered `0` to `39`." This enables optimized encodings to be used in which the values of the top two arcs for all arcs under top-level arcs `0` and `1` encode in a single octet in an object identifier encoding (see the Rec. ITU-T X.690 series \| ISO/IEC 8825 multi-part Standard).

### Child OIDs

- `1.0`: `standard(0)`
- `1.1`: `registration-authority(1)`
- `1.2`: `member-body(2)`
- `1.3`: `identified-organization(3)`

This is a [frozen OID](https://oid-base.com/faq.htm#leaf) (no more child OIDs can be added to the existing ones).

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