A new feature coming from SharePoint 2010 that you can add a barcode in your documents.
Barcode option coming as a content type information policy that you can enable it for any content type inherited from Document content type or inherited from any content type that inherit Document content type.
In this article we will show you how to configure new search metadata and add it to your advanced search properties, for example we have a custom site column with name “ReferenceNo” that we used in many content types and we need to add it in our search properties that the user can use it to filter search results so what we will do is create a SharePoint search “managed property” that refer to this site Column.
In this article we will show how to create search service application
-From central administration home page click on manage service applications.