---
title: "Parent ID Relationship Expectations and Failure Causes"
slug: "parent-id-relationship-expectations-and-failure-causes"
tags: ["id", "field", "family", "relationship", "parent"]
updated: 2025-04-25T06:44:29Z
published: 2025-04-25T06:44:29Z
canonical: "docs.revealdata.com/parent-id-relationship-expectations-and-failure-causes"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.revealdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Parent ID Relationship Expectations and Failure Causes

To identify attachments, the *Parent ID* field, *Attachment* field, or *Family ID* field must be specified. Although only one field is required, it is best to specify either *Parent ID* and *Family ID* or *Attachment* and *Family ID*.

> [!NOTE]
> **Note**
> 
> Specifying all three fields is not recommended because the *Parent ID* field and *Attachment* field can conflict.

Keep the following in mind when specifying these fields:

- If *Parent ID* is available, it should be used instead of *Attachment*.
- If *Family ID* is the only field available, email threading (EMT) will work to identify attachments but only if the *Family ID* values correspond to the key of the parent document.
- The *Family ID* field is not required but should always be specified if available because it is used to populate the *Family ID* field used for indexing and for *EMT_FamilyId* in the Full Report.

If the *Family ID* field is blank, EMT populates it with the key of the parent document.

*Parent ID* should be the unique ID of the parent document in a family of documents, so the parent document should contain its own ID.

If *Parent ID* is being mapped, *Family ID* can contain any random string and does not have to be a document key.

*Family ID* is a unique ID that is used to represent the entire family of documents. This ID should be the *Parent ID* of the family of documents. In the event that it is not the *Parent ID*, Brainspace analytics will also require the configuration of the *Parent ID* field in all documents in the family to properly determine the relationships between parent documents and their attachments.

> [!NOTE]
> **Note**
> 
> In Brainspace v6.1.2, the following misleading log has been corrected: *ERROR {code} [2018-10-03 21:21:58,691] emt errors ERROR - Warning: key WANG_Kai-000257904 has a parentid WANG_Kai-000257898.* It is now shown as an INFO message because it is not an error.

For more information on filed mapping, see [***Field Mapping Categories and Definitions***](/brainspace/docs/field-definitions).

## Related

- [Reveal Archive/Preservation Options for 10.4 SaaS](/reveal-archivepreservation-options-for-104-saas.md)
- [Field Definitions](/field-definitions.md)
- [Error Resolution Troubleshooting Table](/error-resolution-troubleshooting-table.md)
- [Email Threading Overview](/email-threading-overview.md)