Linked record fields by default show all existing records in the record finder. If you would like to ask a client to fill out a form, normally you wouldn’t want them to see all your other clients. Instead of selecting a record from a list, ideally, you would just like them to type in their name (or email, phone, etc) to link their own record. This is exactly what this feature does when it’s enabled in miniExtensions Form.

The way this works is by looking up the linked table to see if the entered data exactly matches any existing records, which will then be available to link.