At the root level there should always be a Component. Check siblings Sibling components or elements should all have a different name. Found multiple components or elements named ''! Check component siblings Sibling components should all be different. Found multiple components with id ''! Check nesting A nested component or element has the same name ('') as this component! Please, consider to rename one of them. The AttributeList child of an element contains a set of XML attributes for that element. When an element is linked to a regular expression or a controlled vocabulary, the ValueScheme sub-element contains more information about this. Specification of a regular expression the element should comply with. A list of the allowed values of a controlled vocabulary. Check reserved attribute names Attribute name shouldn't be 'ref' or 'ComponentId', as these are used internally by CMD! Check attribute siblings All attributes in an attribute list should have a different name. Found multiple attributes named ''! Check attribute nesting An attribute has the same name ('') as its element or component! Please, consider to rename one of them. The name of the attribute. A link to the ISOcat data category registry (or any other concept registry). For the use of simple XML types as the type of the attribute. For the use of a regular expression or a controlled vocabulary as the type of the attribute. The name of the element. A link to the ISOcat data category registry (or any other concept registry). Used to specify that an element has a simple XML type (string, integer, etc) Minimal number of occurrences. Maximal number of occurrences. Some information an application (eg Arbil) can display to give guidance to the user when entering metadata. The element with the highest priority will be displayed as the label for a metadata file (eg in Arbil) Indicates that this element can have values in multiple languages (and thus is repeatable). This will result in the possibility of using the xml:lang attribute in the metadata instances that are created. Indicates that a component (using its unique ComponentId issued by the ComponentRegistry) should be included. A link to the ISOcat data category registry (or any other concept registry). Currently not used. Outdated way of including an external component. Here for backward compatibility with the XML-cmdi-toolkit. cardinality for elements and components Check cardinalities Maximum cardinality (0) cannot be lower than the default minimum cardinality (1)! Minimum cardinality () should be lower or equal then the default maximum cardinality (1)! Minimum cardinality () should be lower or equal then the maximum cardinality ()! Minimum cardinality (unbounded) can't be higher than the (default) maximum cardinality ()! Subset of XSD types that are allowed as CMD type controlled vocabularies An item from a controlled vocabulary. End-user guidance about the value of the controlled vocabulary as a whole. Currently not used. CMD enumeration item All items in an enumeration should be different. Found multiple items with value ''! A link to the ISOcat data category registry (or any other concept registry) related to this controllec vocabulary item. End-user guidance about the value of this controlled vocabulary item.