2.1.2 [XML] Section 2.3, Common Syntactic Constructs

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V0002:

The specification states:

 The Namespaces in XML Recommendation [XML Names] assigns a meaning to names 
 containing colon characters. Therefore, authors should not use the colon in 
 XML names except for namespace purposes, but XML processors must accept the 
 colon as a name character.

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Colons are accepted in names only when they are used in accordance with [NamespacesXML1.1].