X1: Include a reference to the profile XSD generated by the Component Registry [][X1] Each CMD record should refer to an XSD in the Component Registry! X2: Use common namespace prefixes [][X2] Use the cmd: prefix for the CMD envelop! [][X2] Use the xsi: prefix for the schema location attribute! [][X2] Use the cmdp: prefix for the CMD payload! E1: Include a MdSelfLink [][E1] Each CMD record should have a MdSelfLink! E2: The MdSelfLink should be a Persistent Identifier (PID) [][E2] The MdSelfLink should be a Persistent Identifier (PID)! E3: Include a MdCollectionDisplayName [][E3] Each CMD record should have a MdCollectionDisplayName! E4: Include a matching MdProfile [][E4] MdProfile should contain a CLARIN Component Registry profile identifier! [][E4] MdProfile and @xsi:schemaLocation should agree on the profile used! E5: There should be at least one resource proxy [][E5] A CMD record should have at least one Resource Proxy! E6: The URI of a resource proxy should be absolute and resolvable [][E6] A Resource Proxy should have a reference! [][E6] The reference of a Resource Proxy should be absolute! E7: "Metadata" type resource proxies should refer to a CMD record [][E7] A metadata Resource Proxy should point to another CMD record (indicated by the CMDI MIME/media type)! E8: "Metadata" type resource proxies should use PIDs [][E8] The reference of a metadata Resource Proxy should be a Persistent Identifier (PID)! E9: Specify the MIME type of a resource [][E9] The MIME/media type of resource should be specified! E10: "Resource" type resource proxies should use PIDs [][E10] The reference of a resource should be a Persistent Identifier (PID)! E11: Provide no more than one LandingPage [][E11] A CMD record should have no more than one Landing Page! E12: Provide no more than one SearchPage [][E12] A CMD record should have no more than one Search Page! E13: Provide no more than one SearchService [][E13] A CMD record should have no more than one Search Service! E16: Add roles to both relationship participants when considered useful [][E16] Specify the role a resource plays in a relation! [][E16] Add a Concept Link to the role of a resource in a relation! E18: IsPartOf may be used to express a partitive relation between the described resource as a whole and a larger resource or collection [][E18] IsPartOf is not widely used or well supported by the CLARIN infrastructure! E20: Delete foreign attributes before providing [][E20] Strip foreign attributes before providing CMD records!