# Best practices for local extensions (local fields) in NZ-linked records

Local extensions are local fields that can be added to NZ-linked bibliographic records. These fields are marked by a house icon in Alma.

[![local-extension-1.PNG](https://alma-documentation-bookstack.azurewebsites.net/uploads/images/gallery/2024-08/scaled-1680-/local-extension-1.PNG)](https://alma-documentation-bookstack.azurewebsites.net/uploads/images/gallery/2024-08/local-extension-1.PNG)

Specifically, you can enter local information in the MARC 21 77X/78X, 09X, 59X, 69X, and 9XX fields.

The fields only appear to your specific Institution Zone; they do not appear when other institutions are viewing the NZ record.

Local extensions can be added to NZ-linked records either in the Metadata Editor, or in batch via a normalization rule, import profile, or MARCedit.


#### Adding local extensions in the Metadata Editor

After opening an NZ-linked record in the Metadata Editor, choose **Editing actions > Add local extension** to enter a local extension in the bibliographic record.

<p class="callout info">Although not visible in the Metadata Editor, please note that the **$$9 local** subfield is automatically created and stored in the cached record. This subfield will appear in the local extension when exporting the MARC record from Alma.</p>

<p class="callout warning">A local extension should <span style="text-decoration: underline;">**NOT**</span> be added to a record using the **Editing Actions &gt; Add field** function, and then adding a **$$9 local** to the field. This will result in a false "local" field that is actually viewable by all institutions.</p>


#### Adding local extensions via normalization rule / import profile / MARCedit

Local extensions can be added in batch to NZ-linked records using a normalization rule, an import profile, or MARCedit as long as it follows these guidelines

- Can only be a 77X/78X, 09X, 59X, 69X, or 9XX field
- Must add a **$$9 local** (although not visible in Alma, the $$9 local subfield is stored in the cached record)

<p class="callout danger">Non-local fields (those without a $$9 local) CANNOT be added to NZ bibliographic records in batch in an Institution Zone by any method</p>


#### Resources

[Alma Knowledge Center &gt; Adding Local Extensions to Bibliographic Records in the Network Zone](https://alma.wrlc.org/Product_Documentation)

[Alma Knowledge Center &gt; Working with Normalization Rules](https://knowledge.exlibrisgroup.com/Alma/Product_Documentation/010Alma_Online_Help_(English)/Metadata_Management/016Working_with_Rules/020Working_with_Normalization_Rules)