xsi:type, namespaces and preserving lexical values

Dear all,

This is feedback we have related to the EXI specification.

When preserveLexicalValues is true, @xsi:type should be encoded as a string, right?
In the case of preserving lexical values but not preserving namespaces (strict mode for instance),
the EXI stream will not contain any information about the URI of the @xsi:type qname value.
If that is correct, there is a potential issue:

-          Encoder has the URI information

o   Encoder will pick the grammar from the @xsi:type value (according the spec)

-          Decoder has not the URI information

o   It is not able to check whether there is a grammar associated to the @xsi:type value

o   Decoder will pick the default grammar (this my interpretation of the spec)
I am a bit surprised that  @xsi:type dynamic typing would not be usable when preserving lexical values in strict mode...
Anyway, the spec should probably align the EXI encoder behavior with the EXI decoder.

Regards,
                Youenn