Scenario

The user needs to display the customer's Internal ID and External ID as fields on their customer forms.

Solution

1. Navigate to Customization > Lists, Records, & Fields > Entity Fields > New
2. Label: Enter Label (e.g. Internal ID)
3. Type: Select Free-Form Text
4. Store Value: Set to False
5. Applies To: Mark Customer
6. Validation & Defaulting:
   1. Mark Formula
   2. Default Value: Enter {id}
      Note: When creating another field for External ID, use{externalid}
7. Click Save