In section 3.13.2 Cast of XPath 3.0, a new error is introduced.

err:XPDY0129

    The cast failed because the input value is not in the lexical space of the target type (after whitespace normalization as required by the target type).

Yet the text also states that:

"If casting from the input type to the target type is supported but nevertheless it is not possible to cast the input value into the value space of the target type, a dynamic error is raised. [err:FORG0001] This includes the case when any facet of the target type is not satisfied. For example, the expression "2003-02-31" cast as xs:date would raise a dynamic error."

What conditions does XPDY0129 catch which are not already caught by FORG0001 (Invalid value for cast/constructor.) or indeed err:FOCA0002 (Invalid lexical value).

Note that XPDY0129 is not mentioned in section 18 Casting of F&0 3.0.