Whitespace Treatment in Attributes
A related issue to the text/token issue in Whitespace Treatment in Terminal Elements is the use of string versus token in attribute types. Again, white-space is not significant, other than as a token separator, so token should be used rather than string.
Because xsd:token is the default base datatype for attributes in Relax NG, this fix was implemented within the Relax NG Schemas as early as version 1.0. This was propagated to the XSD schemas in version 1.01 when the automatic generation of the XSDs was implemented.