f:Extension extension with URL = 'igCanonicalUrl': minimum cardinality of 'extension' is 1 extension with URL = 'igCanonicalUrl': maximum cardinality of 'extension' is 1 extension with URL = 'igPackage': maximum cardinality of 'extension' is 1 extension with URL = 'igVersion': maximum cardinality of 'extension' is 1 value[x]: maximum cardinality of 'value[x]' is 0 f:Extension/f:extension id: maximum cardinality of 'id' is 1 url: minimum cardinality of 'url' is 1 url: maximum cardinality of 'url' is 1 value[x]: minimum cardinality of 'value[x]' is 1 value[x]: maximum cardinality of 'value[x]' is 1 id: maximum cardinality of 'id' is 1 url: minimum cardinality of 'url' is 1 url: maximum cardinality of 'url' is 1 value[x]: minimum cardinality of 'value[x]' is 1 value[x]: maximum cardinality of 'value[x]' is 1 id: maximum cardinality of 'id' is 1 url: minimum cardinality of 'url' is 1 url: maximum cardinality of 'url' is 1 value[x]: minimum cardinality of 'value[x]' is 1 value[x]: maximum cardinality of 'value[x]' is 1 id: maximum cardinality of 'id' is 1 url: minimum cardinality of 'url' is 1 url: maximum cardinality of 'url' is 1 value[x]: minimum cardinality of 'value[x]' is 1 value[x]: maximum cardinality of 'value[x]' is 1