A smart object's settings specify it's capabilities, how it is accessed, and which fields are available for reporting.
General
Record Key - Specify the field or combination of fields that will be used as the record key, for import and remote get , upsert , post perations.
The options are:
Unique Random ID -
{some field} - Choose one of the fields that have been defined for the object.
Combination Key - Select one or more fields, and add any text desired to separate them.
Record Identifier - Choose a single field that will identify the record to the user in record list or report.
Select Custom Identifier to join the contents of one or more fields, plus any text needed to create something the user will recognize.
Allow Notes to be added to Records - Adds an Activity tab to smart object records. Notes can be added to the record, and emails can be sent, and all activities are recorded.
Allow Attachments to be added to Records - Allows users to attach files to the smart object records.
Reporting Fields
In the Reporting Fields tab, select that fields that will be available for reports.
Display Order
Choose which Smart Objects to display, and the order in which they appear.
Edit the default order, and add additional orderings for selected profiles.