# NodeID has to have a value?

**Category:** [Reference Implementation: Java (archive)](https://discourse.openehr.org/c/reference-implementation-java-archive/154)
**Created:** 2008-11-18 14:40 UTC
**Views:** 6
**Replies:** 1
**URL:** https://discourse.openehr.org/t/nodeid-has-to-have-a-value/13074

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## Post #1 by @Filip_Klasson

Hi, i am wondering if NodeID for all CObjects is something that has to have a value? In the AOM documentation it says: "Semantic id of this node, used to differentiate sibling nodes of the same type. [Previously called 'meaning']. Each node_id must be defined in the archetype ontology as a term code."

According to the soruce code of LinkEHR NodeID has to exist. I am just trying to make sure that is the case.

Cheers

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## Post #2 by @thomas.beale

Filip Klasson wrote:

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**Canonical:** https://discourse.openehr.org/t/nodeid-has-to-have-a-value/13074
**Original content:** https://discourse.openehr.org/t/nodeid-has-to-have-a-value/13074