Formula field on custom record, how to reference internal id

AI generated answer (using internal Slack threads):

To reference the internal ID in a formula field on a custom record, you can use the

.id

notation. This is always available and is the only 3rd level join you can achieve. For example, if you have a custom field that needs the ID as a string, non-stored value then you can source in the internal ID of the list by doing

{customfieldwithlistid.id}

under "Validation & Defaulting" --> Default Value. If you are trying to get the internal ID of a customer from a project task, you might need to create a custom field first on the Project record and source the internal ID of the customer in it. Then on the task record's custom field, you can source the custom field value from the Project record. Since you cannot go more than 2 levels, you will have to first source the internal ID on the project record itself and then on Task record. For example,

{job.customer.id}

. For items, there is an External ID field. However, by default, you cannot access it from the UI. You can set the external ID (unique) for the records via CSV. To show it in UI, use a custom field and source "external id" value from the native field. You can also add a custom text formula field with the formula just being

{externalid}

then it will show whenever anyone brings up the form. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******