The TCK contains a few tests which are based on an implicit assumption but without an explicit sentence in the spec. I think we should add these missing pieces:

• The following assertion is not made explicitly by the spec, however it is implied: The type of the groups parameter is Class<?>[].
• The following assertion is not made explicitly by the spec, however it is implied: META-INF/validation.xml will be ignored if Configuration.ignoreXMLConfiguration() is called.