The Default domain in ServiceNow is specifically used for the following purposes:

1.Help identify integrations that are incorrectly creating global data: The Default domain can be used to track and identify any integrations that are mistakenly creating data in the global domain instead of the intended specific domain. This helps in maintaining data integrity and ensuring that data is correctly segregated.

2.Capture records with no domain on tables that should not have global data: The Default domain is also used to capture records that do not have a domain specified on tables where global data should not be present. This ensures that such records are not incorrectly placed in the global domain, maintaining the separation and security of data.

For more detailed information, you can refer to the following resources:

•ServiceNow Support Article on Domain Separation

•Developing Domain-Separated Applications