You can use the withProperties query parameter to specify whether additional information from specific tables columns are returned in the response.
NOTE: To enable table columns for these queries, set the Show in wizards option in the column properties of the relevant columns in the Designer.
TIP: You can delimit the names of multiple columns with commas.
Example
The following query determines the number of all identities and also returns their preferred name and title:
https://<host name>/ApiServer/portal/person/all?withProperties=PreferredName,Title
Response:
{ | 
"TotalCount": 105950,  | 
"TableName": "Person",  | 
"Entities": [  | 
        { | 
"Display": "100, User (USER1)",  | 
"LongDisplay": "100, User (USER1)",  | 
"Keys": [  | 
"bbf3f8e6-b719-4ec7-be35-cbd6383ef370"  | 
],  | 
            "Columns": { | 
                "DefaultEmailAddress": { | 
"Value": "USER1@qs.ber",  | 
"IsReadOnly": true  | 
},  | 
                "IdentityType": { | 
"Value": "Primary",  | 
"IsReadOnly": true,  | 
"DisplayValue": "Primary identity"  | 
},  | 
                "PreferredName": { | 
"Value": "Johnny",  | 
"IsReadOnly": true  | 
},  | 
                "Title": { | 
"Value": "Dr.",  | 
"IsReadOnly": true  | 
},  | 
                "XObjectKey": { | 
"Value": "<Key><T>Person</T><P>bbf3f8e6-b719-4ec7-be35-cbd6383ef370</P></Key>",  | 
"IsReadOnly": true  | 
}  | 
}  | 
}  |