# Element not allowed units_system in element list

**Category:** [ADL](https://discourse.openehr.org/c/adl/40)
**Created:** 2025-10-01 10:45 UTC
**Views:** 141
**Replies:** 9
**URL:** https://discourse.openehr.org/t/element-not-allowed-units-system-in-element-list/11467

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## Post #1 by @Yasitha_Thilantha

I created an archetype with the RM type **C_DV_QUANTITY** using the *Better Archetype Designer* tool. 
Then I created a template based on the above archetype and tried to validate it using the **ehrbase-openehr-sdk** Java library. However, I got this error:
Element not allowed: units_system in element list

This is the code segment in the OPT file that triggered the error.

![image|491x500](upload://1deZ8Q6x8Q301PL7aPB8Y5zJrks.png)

I was unable to find `units_system` and `units_display_name` in the official openEHR schema specification.
Are these custom elements introduced by the Better Archetype Designer tool?
If so, how can I validate my OPT file against the openEHR standards?

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## Post #2 by @matijap

Those attributes were added in Reference Model 1.1.0 release in 2020. Not sure what schema specification you are referring to.

[DV_QUANTITY specification](https://specifications.openehr.org/releases/RM/latest/data_types.html#_dv_quantity_class)

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## Post #3 by @Yasitha_Thilantha

I’m using the openEHR_SDK version 2.26.0 to validate template `.opt` files in my application.

This is the schema used by the Java library:
[https://github.com/ehrbase/openEHR_SDK/blob/release/v2.26.0/opt-1.4/src/main/xsd/BaseTypes.xsd](https://github.com/ehrbase/openEHR_SDK/blob/release/v2.26.0/opt-1.4/src/main/xsd/BaseTypes.xsd)

The SDK appears to be using the ITS XML schema version 1.0.2.
After investigating openEHR releases, I found the following:

* **RM Release 1.1.0** (29-Sep-2020): This RM model includes the elements you mentioned.

* **ITS-XML Release 2.0.0** (26-Apr-2021): This release includes the ITS along with the compatible XSDs.

However, even in the latest ITS release, the stable XML schemas are still marked as version 1.0.2:

* [https://specifications.openehr.org/releases/ITS-XML/Release-2.0.0](https://specifications.openehr.org/releases/ITS-XML/Release-2.0.0)

It seems that the new changes introduced in RM Release 1.1.0 have not yet been incorporated into the stable ITS release. I believe that’s why the `openEHR_SDK` v2.26.0 Java library is still using the older 1.0.2 XSDs.

As a result, I’m still getting the 1.0.2 stable XSDs from the ITS release.

Do you have any idea why openEHR hasn’t released updated XSDs with the latest RM changes in the ITS releases?

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## Post #4 by @matijap

I don’t, but I’ll open this topic on the specifications committee meeting next week and get back to you.

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## Post #5 by @matijap

So the conclusion basically is that the XSD models refer to an old version, while not explicitly stating that. Our plan is to add a note/statement to that accord ASAP, and then soon after that bring the XSD up to date. Thank you for noting the discrepancy!

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## Post #6 by @Yasitha_Thilantha

Thanks for the clarification! That sounds like a good plan . Do you also have an estimated timeline for updating the SDK Java library accordingly (ITS release)?

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## Post #7 by @matijap

No; perhaps @sebastian.iancu can comment on that.

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## Post #8 by @ian.mcnicoll

Actually, I think that openEHR SDK library is from Ehrbase - perhaps @vidi42 can comment?

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## Post #9 by @Yasitha_Thilantha

We encountered another validation error:
**Invalid xsi:type qname: 'C_DV_SCALE' in element attributes@[http://schemas.openehr.org/v1](http://schemas.openehr.org/v1)**

The **DV_SCALE** type was introduced in **RM Release 1.1.0**:
[https://specifications.openehr.org/releases/ITS-XML/Release-2.0.0/components/RM/Release-1.1.0/DataTypes.xsd](https://specifications.openehr.org/releases/ITS-XML/Release-2.0.0/components/RM/Release-1.1.0/DataTypes.xsd)

However, it is not available in the latest ITS release. The stable XML schemas are still marked as version **1.0.2**, and the **openEHR_SDK v2.26.0** Java library is still using these older **1.0.2** XSDs.

Do we have any updates or plans to bring the XSDs up to date and update the SDK Java library accordingly (ITS release)?
@matijap, @vidi42 , @ian.mcnicoll

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## Post #10 by @ian.mcnicoll

I’ll bring it up at the next SEC call.

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**Canonical:** https://discourse.openehr.org/t/element-not-allowed-units-system-in-element-list/11467
**Original content:** https://discourse.openehr.org/t/element-not-allowed-units-system-in-element-list/11467